BRIEF COMMUNICATION: An evaluation of the AGTECH360 Livestock Tracker for the automated recording of on-farm grazing events. - WA Hofmann; JP Edwards; MB Neal (New Zealand Journal of Animal Science and Production, 2023)
Many New Zealand farmers either do not record paddock grazing events or do not retain grazing data after making decisions about cow feeding and pasture management. This study, conducted at the Northland Agriculture Research Farm (NARF), aimed to determine whether GPS-enabled devices suitable for use on cattle could be used to automate the recording of grazing events on-farm. Accordingly, 12-13 cows within each of the three herds (herd size range 59- 85 cows) were fitted with an AGTECH360 Livestock Tracker from 1 December 2021 to 31 March 2022. The GPS location data were then compared with manual grazing records. The grazed paddock was correctly identified on 80- 92% of occasions, depending on the herd. These results indicate that it is feasible to automate the recording of onfarm grazing events by fitting a proportion of the herd with GPS-enabled devices. Keywords: dairy farm systems; grazing records; global positioning systems (GPS); Internet of Things (IoT); low-power wide-area network (LPWAN); LoRa

BRIEF COMMUNICATION: Approaches to breeding heat tolerant dairy cattle - EG Donkersloot; GM Worth; LR McNaughton; A Yeates; SR Davis; RJ Spelman (New Zealand Journal of Animal Science and Production, 2023)
Climate change will become increasingly problematic for grazing cattle, with heat stress impacting both animal welfare and productivity. Genetic strategies are available to mitigate heat stress, some of which such as crossbreeding, have already been tested in tropical climates. Heat tolerance is a heritable trait in dairy cattle and genetic progress can be achieved using genomic selection, an approach adopted in Australia. Another strategy is to introgress the SLICK genetic variant from Senepol beef cattle into dairy cattle. This enables a 0.5 to 1.0 °C advantage in rectal and ruminal temperature, relative to control cows, when under a mild heat load. This variant has already been introduced into breeds of beef cattle by gene editing, an approach which promises to greatly accelerate gene introgression for single gene traits and lessen the potential impact of introgression on inbreeding in a population. Keywords: heat tolerance, dairy cattle, SLICK, breeding

BRIEF COMMUNICATION: Considerations to cost-effectively automate batch milking in pastoral dairy systems without distributing milkings over 24 h. - JP Edwards; BT Dela Rue; JG Jago (New Zealand Journal of Animal Science and Production, 2023)
Current technological limitations mean that to cost-effectively automate batch milking, without distributing milkings over 24 h, a rethink of the farm and milking system is required. A model and a range of non-optimised scenarios were developed for a 300-cow herd to illustrate the trade-offs between the number of automated milking points required (cost) and the duration of ‘on-call’ time for the person overseeing milking. Compared to the base scenario of 30 milking points (equivalent to conventional milking), by milking the herd in three groups of 100 and adjusting the twice-a-day milking interval from 9-15 h to 6-18 h, the number required could be reduced to 12, with a similar ‘on-call’ time. Further adjustments could reduce the number of milking points to 7 by milking once-a-day, although five groups of 60 cows would be required to keep cow waiting time below 2 h. These results demonstrate the potential flexibility of current automated milking technology for batch milking. Keywords: dairy farm systems; automated milking; batch-milking

BRIEF COMMUNICATION: Effects of the SLICK gene on heat tolerance in grazing dairy cattle - GM Worth; EG Donkersloot; RJ Spelman; SR Davis (New Zealand Journal of Animal Science and Production, 2023)
The heat tolerance of Senepol beef cattle (Bos taurus) has been causally linked to a mutation in the prolactin receptor (PRLR) on BTA20. This variant of PRLR has become known as the SLICK gene because it is also associated with a short-hair coat. We have investigated the heat tolerance of New Zealand dairy cattle bred to carry the SLICK gene, using measurement of vaginal temperature. Hair length differed (P<0.001) between SLICKs and controls at the neck (4.3 ± 0.5 mm vs 13.8 ± 1.2 mm, respectively), shoulder (6.5 ± 0.7 mm vs 14.9 ± 1.5 mm, respectively) and pin bone (6.9 ± 0.6 mm vs 15,2 ±1.4 mm, respectively). Vaginal temperatures of SLICK animals were 0.5 - 1°C lower than controls at peak ambient temperature (28.4°C; 16.00h). SLICK dairy cattle show a markedly improved ability for temperature homeostasis under mild heat load, relative to control cattle. Keywords: heat tolerance; dairy cattle; SLICK; genetics

BRIEF COMMUNICATION: Maternally supplemented L-glutamine increases growth rates of twin lambs from birth - LJ Dunstana; ML Hebarta; FD Briena; SA McCoard; M Caetano (New Zealand Journal of Animal Science and Production, 2023)
Abstract Fertility is a fundamental phenotypic trait used for achieving optimal production efficiency and, no easily adoptable or precise tools are currently available. In this study, anogenital distances (AGD; anus to clitoris - AC and anus to fourchette - AF) were measured twice from 80 Merino ewes and 80 ewe hoggets to predict fertility. Fertility was measured by evaluating the pregnancy scanning results. Measurements of ADG were performed by using digital callipers and high-resolution images. Overall means of measures were greater for the AF in pregnant ewes compared to dry ewes and no association was found for the AC distance except being shorter for hoggets with callipers. The relationship found between one of the AGD, the AF, and pregnancy status demonstrates the potential to use this trait as a cost-effective method for estimation of fertility that can be easily adopted by producers, particularly in hoggets. Keywords: breeding, clitoris, imaging, pregnancy status, sheep

BRIEF COMMUNICATION: The Efficacy of Natural Substances to Protect Dietary Glutamine from Ruminal Degradation - LP Carlyon; TR Boyce; LJ Flanagan; RC Alves; K Petrovskix; M Caetano (New Zealand Journal of Animal Science and Production, 2023)
In ruminants, the rumen protection of amino acids is required to prevent microbial degradation and increase the portion of undegradable dietary protein; therefore, increasing the total concentration of amino acids absorbed in the small intestine. The conditionally essential amino acid, glutamine, is vital to an array of biological processes throughout the body. The objective of the current study was to validate and optimise the use of two natural substances (NS1 and NS2) to rumen-protect glutamine from microbial degradation. Encapsulated glutamine has been tested in triplicate using an in vitro approach. It was concluded that, both natural substances provided protection to glutamine resulting in a 33.83% and 10.66% decrease in ammonia release with NS1 and NS2 respectively. Keywords: amino acids, in vitro test, protein, rumen microorganisms, ruminants

Analysis of ewe body condition scores from selected flocks in the North Island of New Zealand - Ridler AL; Flay KJ; Kenyon PR; Lawrence KE; Corner-Thomas RA (New Zealand Journal of Animal Science and Production, 2022)
Ewe body condition score (BCS) is known to be associated with many ewe production traits. Descriptive and multivariate analyses were undertaken on existing datasets comprising 266,405 BCS observations from 86,444 individual two-tooth and mixed-age ewes on six commercially managed sheep farms in the North Island of New Zealand. The BCS observations were collected at pre-breeding, pregnancy diagnosis, set-stocking and weaning between the years 2009-2021. Overall, the majority of BCS observations were 2.5 or 3.0 while 9.7% were BCS <2.5. At the key management times of pre-breeding and set-stocking, when it is recommended that ewes should be BCS 3.0 and above, 39% and 50% respectively of ewes were BCS <3.0. Mixed-age ewes had greater odds of being BCS <2.5 compared with two-tooth ewes, but with variation between BCS observation time, farm and year. While these data are from only six farms, if they are indicative of other North Island sheep farms they demonstrate significant room for improvement in individual ewe BCS for optimal production.

BRIEF COMMUNICATION: Behaviour and physiology of lambs with gastrointestinal nematode parasitism - Hempstead MN; Waghorn TS; Gibson MJ; Sauermann CW; Ross AB; Cave VM; Sutherland MA; Sutherland IA (New Zealand Journal of Animal Science and Production, 2022)
The behaviour and physiology of lambs with gastrointestinal nematode infections (GIN) was evaluated. Thirty 8-month-old Romney wethers were assigned to one of two treatments (n=15/treatment) trickle dosed with either 1500 infective third stage larvae 3 days/week for 6 weeks (27,000 total L3; challenged), or water 3 days/week for 6 weeks (control). Blood and faecal samples were collected weekly during the study. Lipidomics were performed on plasma samples. Behaviour was observed from video-camera recordings once weekly over the study. At treatment week 4, specific triglycerides were elevated in the challenged lambs compared to controls (P≤0.05). Faecal egg counts were higher in challenged than control lambs from treatment week 4 (154 epg; P≤0.001). Challenged lambs had higher standing bouts at week 4 than baseline (5.6 bouts) whereas there were no differences in standing bouts for control lambs between baseline and week 4. Triglycerides and standing behaviour show promise for early identification of GIN.

Comparison of associations between estimated breeding values and cow survival in herds being milked once or twice a day - Edwards JP; Zhang X; Stachowicz K; Waters ACL; Amer PR (New Zealand Journal of Animal Science and Production, 2022)
The objective of this study was to investigate the link between estimated breeding values (EBV) for selected traits, including Traits Other than Production (TOP), and cow survival in herds milked once-a-day (OAD), and to contrast with herds milked twice-a-day (TAD). After filtering, data from 234 OAD herds (71,321 cows) and 234 TAD herds (75,123 cows) were extracted from the Dairy Industry Good Animal Database between 2007 and 2021. Cow survival from parities 1 to 2, 2 to 3, 3 to 4, 4 to 5 and 5 to 6 (S12, S23, S34, S45 and S56) were modelled within each milking frequency and age parity group, with trait EBVs fitted as covariables and the fixed effect of herd-year, using a generalised linear model with a gaussian kernel. The survival rate in OAD cows was higher than in TAD cows in S12 and less in S34 to S56. Udder support EBV became important in older cows (S45 and S56) but there were no significant differences between OAD and TAD herds. Compared to OAD herds, Fertility EBV had a greater effect on survival in TAD herds up to S34, as did Body Condition EBV for S12. Conversely, milk Volume, Fat, Protein and Somatic Cell Score EBVs had smaller effects on survival in TAD herds. Our results do not contain evidence that warrant greater selection pressure on functional traits in OAD systems relative to TAD to enhance animal survival. When selecting sires, selection pressure could be reduced on some traits, such as Fertility and Body Condition, in OAD systems, with a greater emphasis placed on production and milk composition.

A comparison of the performance Romney and Wiltshire cross lambs to weaning - Corner-Thomas RA; Ridler AL; Kenyon PR; Andrews CJ; Burnham DL; Blair HT; Morris ST (New Zealand Journal of Animal Science and Production, 2022)
New Zealand coarse-woolled sheep farmers today barely recover the costs of shearing. One option is to introduce a self-shedding breed such as the Wiltshire. A strategy to transition to a Wiltshire flock is to cross a ewe flock with Wiltshire rams and in subsequent years backcross with Wiltshire rams. The first year of a long-term study found the performance of first cross Wiltshire progeny were not different to the base Romney flock in terms of birth weight and growth to weaning. The ewe lambs from this first breeding were then bred as ewe lambs to Wiltshire rams in late April 2021 to generate ¾ Wiltshire lambs. There were no differences (P>0.05) in fertility or fecundity between the ½ Wiltshire cross or Romney ewe lambs. There were no differences in birth, docking or weaning weight with the exception that single-born ¾ Wiltshire cross lambs had higher growth (P<0.05) from birth to weaning than their Romney counterparts. This effect was not (P>0.05) observed in twin lambs. Combined these results indicate to date that there are no negative impacts of introducing Wiltshire rams to a mixed-age Romney ewe flock in relation to ewe performance to 15 months of age and the performance of their ¾ progeny to weaning.

Comparison of two milk replacer formulations on the growth, health and purchased feed costs of artificially rearing male dairy-sheep lambs using a restricted milk intake feeding system and early weaning - McCoard SA; Birch D; Hea, S-Y; Maclean P (New Zealand Journal of Animal Science and Production, 2022)

Deer seasonal growth pathways - Thompson BR; Stevens DR; Ward JF; Dodds KG; Asher GW (New Zealand Journal of Animal Science and Production, 2022)
Red deer are seasonal and generally experience a period of low growth in winter. Previous research has demonstrated that individuals vary in the degree of their seasonality. Mechanisms that drive the differences in seasonality are not well understood. Six sires paired by 12-month weight estimated Breeding Value (eBV) but with contrasting seasonality were used to generate progeny to investigate the mechanisms that influence seasonal growth. Progeny were fed ad-lib on pasture year-round to allow expression of genetic potential with liveweight monitored fortnightly. Feed intake and efficiency were estimated during a 10-day period in each season. Analysis of seasonal liveweight gains indicated that predicted seasonal growth rates were repeatable within sire lines. Significant differences within paired sire lines in growth rates were expressed during winter for the two lower 12-month weight eBV paired groupings. Winter intakes were estimated to be lower than spring intakes although absolute values were considerably higher than expected. Variations in estimated feed efficiency between sire-line pairings were significant in all seasons apart from summer however, more research is required to correlate this estimation technique against actual feed efficiency. This research demonstrated that variation in the degree of seasonality between sires does exist and could be exploited for management decisions.

Does silage containing Plantain affect the urination behaviour and urinary nitrogen of dry cows grazing diverse or conventional pasture? - Brown TM; HMGP Herath; Beckett BP; Bryant RH; Al-marashdeh O (New Zealand Journal of Animal Science and Production, 2022)
The objective of this study was to investigate the effect of diverse silage containing plantain on urination behaviour and urinary and faecal nitrogen (N) concentration of dairy cows when grazing standard ryegrass-white clover (RGWC) or diverse pasture containing plantain. Four groups of six non-lactating dairy cows were balanced and randomly assigned to one of four dietary treatments in a 2 × 2 factorial design: RGWC pasture plus RGWC silage; RGWC pasture plus diverse silage containing plantain; diverse pasture plus RGWC silage; diverse pasture plus diverse silage. Urination behaviour (frequency and volume) was continuously measured for a minimum of 24 hours on four cows per treatment using the Lincoln University PEETER V1.0 sensor. There was no silage or silage × pasture type interaction effects on urination behaviour, though diverse pasture regardless of silage increased daily urination frequency (p=0.046) and daily urine volume (p=0.003) of cows by 27% and 31% respectively, compared to RGWC. Spot urine N% concentration was similar among treatments, but faecal N% tended (p=0.07) to be higher in cows grazing diverse pasture compared to those grazing RGWC with no silage type effect. Unlike fresh plantain, silage containing plantain does not seem to alter urination behaviour or N excretion of dairy cattle. Keywords: Plantago lanceolata L; dairy cattle; winter study; urination frequency

Does the source of drinking water (bore vs town supply) influence water intake, milk production and cow drinking preferences? - K, Schütz; Huddart F; Hardie E (New Zealand Journal of Animal Science and Production, 2022)
Cows are sensitive to drinking water quality, however, little is known about the perception of bore water that sometimes contain high concentrations of natural contaminants, such as iron and manganese. Our aim was to investigate if providing drinking water from town supply compared with unfiltered bore water would influence water intake, milk production and cow preferences. Four groups of cows (50 cows/group) milked once-a-day in autumn were offered either town supply water or unfiltered bore water for two weeks, before changing treatment for another two weeks in a cross-over design. Group water intake and individual milk production was measured daily (n=4 groups/treatment). Water source did not influence water intake or milk production (P≥0.641). A preference study on a subset of animals was undertaken after the initial trial period in which two groups of cows (n=2, 20 cows/ group) had free access to both water sources simultaneously for three days. Cows preferred to drink the unfiltered bore water compared to town supply (descriptive data). It is likely that the cows’ previous experience with drinking the unfiltered bore water influenced the results. The cows may also have perceived components of the town supply aversive compared to the bore water to which they were accustomed.

Drinking behaviour of ewes with access to a water trough during summer and autumn - a preliminary examination - Corner-Thomas; Bunyaga AS; Draganova I; Burkitt L; Kenyon PR (New Zealand Journal of Animal Science and Production, 2022)
Three observational studies were conducted to determine the water intake behaviour of ewes during the summer of 2017 and autumn of 2018 in the Manawatū and summer of 2021 in the Wairarapa. In each study, ewes were offered ad-libitum access to water from reticulated water troughs with video cameras recording footage of ewe drinking behaviour. Ewes were fitted with a uniquely numbered collar and spray marked with an identification number on their flank. Proximity of ewes to the water trough was determined using Bluetooth technology. Maximum daily temperatures ranged between 17.2 and 25.5°C in study 1, 9.9 and 23.6°C in study 2 and 16.0 and 28.1°C in study 3. Pasture moisture content was greater than 70% in both the Manawatū studies and less than 60% in the Wairarapa. Eighty percent of ewes in 2017 and 45% in 2018 were not observed to drink from the water trough at any time in the Manawatū, although, there was considerable intra-animal variation. In the Wairarapa, all ewes were observed to drink during the study on between one and 14 occasions. These studies suggest that ewe drinking behaviour showed considerable variation between individuals and is likely dependent on the environmental conditions and pasture moisture content.

Effect of breed on bone morphology in the distal metacarpus epiphysis of mature Angus and Angus crossbred cows - Gibson MJ; Hickson RE; Dittmer KE; Back PJ; Schreurs NM; Rogers CW (New Zealand Journal of Animal Science and Production, 2022)
There are variations in stature between beef and dairy breeds (and their crosses) which are an indirect result of genetic selection and farm management for different production objectives. The aim of this experiment was to examine the effect of breed on bone morphology in the distal epiphysis of the metacarpus. The metacarpus was collected from 9.5-year-old Angus (AA), Angus-Friesian crossbred (AF), Angus-Jersey crossbred (AJ) and Angus- (Friesian cross Jersey) crossbred (AK) cows. Bone morphology in the epiphysis was assessed using peripheral quantitative computed tomography (pQCT) for the medial and lateral condyles of the epiphysis 7 mm from the distal metacarpus. The greater total bone cross-sectional area of AA and AF could be associated with minimising strain on the articulating surface of the metacarpus due to greater joint surface area. Therefore, the greater total bone cross-sectional area may be an indirect result of a greater level of muscularity in beef breeds with a heavier mature weight.

Evaluating loafing surfaces for off-paddock facilities on New Zealand dairy farms - Beukes PC; Dela Rue B; Dalley DE; McCall D (New Zealand Journal of Animal Science and Production, 2022)
Off-paddock wintering facilities need loafing surfaces that meet animal welfare requirements. Our objectives were to establish relationships between dairy cow behaviour and firmness (comfort) and traction (non-slip) across four different loafing surfaces. The four surfaces were post peelings (woodchip), a 50 mm shredded rubber playground surface with 6 mm geotextile overlay (NUMAT), a 25 mm rubber and plastic chip sports turf underlay with 6 mm geotextile overlay (Tiger Turf), and 25 mm × 1 m2 interlocking rubber matting (NUMAT). Average daily cow lying times were 11.5, 11.0, 10.5 and 8.0 hours/day for post peelings, shredded rubber, rubber/plastic chip, and rubber matting, respectively. A Clegg hammer impact soil tester (2.25 kg) used for mechanical measures of firmness (comfort) showed a strong negative curvilinear relationship with lying times. A Rotational Traction Tester for measuring traction (non-slip) indicated the least to most slippery surface was post peelings followed by shredded rubber, rubber/plastic chip, and finally, rubber matting, which aligned with anecdotal observations of slipping events. Threshold values for these mechanical tests are proposed that will help with evaluating innovative surfaces for cow comfort without the need for animal trials.

Factors that may lead to heat-stress in pigs during road transport - Dobinson SSA; Hickford JGH (New Zealand Journal of Animal Science and Production, 2022)
A preliminary observational study was undertaken to examine the effect of road transport on finisher pigs that were being transported to an abattoir in New Zealand. Temperature and humidity within a stock-truck were recorded during multiple trips over a three-year period and a video camera was employed to observe the behaviour of the pigs that were being transported. The videos produced were used to establish the times at which open-mouth breathing (OMB; an indicator for heat-stress in pigs) commenced. The videos revealed that OMB was found to occur throughout the year, including during the winter months, but that it occurred mostly during stationary periods when the truck stopped for driver breaks. A temperature-humidity index was utilised to ascertain what may have triggered the OMB and it was observed that the behaviour typically started when that index reached 72. The study suggests that the welfare of pigs may have been compromised by heat-stress over many of the journeys that were monitored. Keywords: heat-stress; pigs; temperature-humidity index; transport stress

Genetic parameters for velvet antler of farmed red deer and wapiti - Ward JF; McIntyre SB; Jopson NB; Newman S-AN (New Zealand Journal of Animal Science and Production, 2022)
Deer breeding in New Zealand has historically paid little attention to quantitative genetic methods to improve the cut weights of velvet antlers. To provide enhanced breeding values for velvet antlers genetic parameters were estimated for DEERSelect. Velvet antler weight data was obtained from 21 red deer and 7 wapiti breeding studs and uploaded to DEERSelect. These data consisted of > 50,000 records from 25,087 individuals and 1,419 sires. Mean velvet weights ranged from 2.71 (±1.01) at 2-years, to 5.79 (±1.98) at 10-years of age. Estimates of heritability at different ages were moderately high (0.33-0.44), but lower than previously reported estimates. Genetic correlations were high at all ages, phenotypic correlations were lower, both were similar to those reported previously. The genetic and phenotypic correlations between 12-month liveweight and 2-year-old and mature (i.e., ≥ 3 -year-old) velvet weights were low (0.15 ± 0.03, 0.02 ± 0.03) and low-moderate respectively (0.24 ± 0.08, 0.18 ± 0.01). These updated genetic parameters encouraged an update of the DEERSelect velvet module. The moderate heritability estimates should encourage breeders to make much more use of this quantitative genetic tool to breed more accurately for increased velvet antler weights.

Genome-wide association studies for milk traits in New Zealand dairy sheep - Costilla R; Chan PB; Mcrae KM; McEwan JC; Dodds KG; Newman SA; Baird HJ; Henry H (New Zealand Journal of Animal Science and Production, 2022)
The New Zealand dairy sheep industry has grown markedly in the last decades. With better genetics and management, companies have been able to improve key production traits. This study aimed to identify single nucleotide polymorphisms (SNPs) associated with milk traits in dairy sheep. We performed genome-wide association (GWA) analyses for milk yield, fat and protein content using data from commercial farms. We used 54,698 milk yield records and 24,891 fat and protein records from 4,590 and 2,823 ewes, respectively. Phenotypes were collected between August 2018 and April 2021 across three locations in New Zealand. They were adjusted for flock, age, lactation, lambing date, weeks in milk and permanent environment. Animals were genotyped with commercial SNP chips with 13,759 markers available after quality control. GWA models included the genomic relationship matrix, three principal components and genomic inflation correction for the p-values. We found four genome-wide significant associations for milk yield. These variants were mapped to eight genes, PDZRN4 (intron), EDEM2, PROCR, MMP24 (intron), EIF6, FAM83C, UQCC1, and HDAC9 (intron). Of these, PDZRN4, HDAC9 and MMP24 were associated with milk traits in previous studies. No significant associations were found for fat and protein content. Genes shown here are promising candidate genes, requiring validation in independent samples.

Impact of maternal diet during late gestation and pre-weaning milk allowance on heifer growth and first lactation milk yield - Moonsan Y; Thomas C; McCoard SA; Hammond KJ; Edwards GR; Bryant RH (New Zealand Journal of Animal Science and Production, 2022)
A total of 60 Friesian x Jersey heifer calves were allocated to a 2×2 factorial design to investigate early life nutrition on growth and production. The first factor was the maternal treatments where dams were offered a low crude protein (7.8% LCP) or moderate crude protein (13.6% MCP) diet for the last 50 days of gestation. The second factor was the calf milk replacer (CMR) allowance to heifer offspring, which was either restricted (RES) or high allowance (HA) allowance (15 or 25% of initial live weight, respectively). All calves were given colostrum for 4 days then, warmed CMR (150 g/L) in two equal feeds between days 5 and 39, after which all calves received the same 15% allowance. Milk intake, liveweight gain and fecal score were recorded for 5 weeks. Calves were weaned off milk at 8 weeks of age. The HA treatment improved weaning weight (88 vs 79±1.4 kg; P<0.001) and overall ADG pre-weaning (0.9 vs 0.8±0.02 kg/day; P<0.001) compared to RES. There was no effect of maternal diet on pre-weaning growth or fecal score. There was limited statistical evidence of a long-term effect of early life nutrition on milk yield, though maternal nutrition appeared to be more important than pre-weaning nutrition on future milk production.

Modelling winter feeding practices with fodder beet in growing and dry dairy cattle - Jonker A; Dalley DE; Woods RR; Dynes RA; Pacheco D; Khan MA; Edwards JP; Hammond KJ (New Zealand Journal of Animal Science and Production, 2022)
The objective of this study was to use the Large Ruminant Nutrition System simulation (LRNS) model to evaluate inclusion of different proportions of fodder beet (FB) with several feed supplements to determine if these dietary combinations meet the nutrient requirements of dry cows and growing one-year-old (R1) heifers over winter. The LRNS simulations demonstrated deficiencies in Ca and P when diets contained 60 and 80% of FB, especially for dry cows up to 21 days before calving and in R1 heifers. When FB comprised 60-80% of the diet of R1 heifers, there was insufficient metabolisable protein to support maximum average daily gain and insufficient physically effective neutral detergent fibre (peNDF) in diets containing over 60% FB. Diets containing more than 40% FB had a negative rumen degraded protein balance (RDPB) and an excess non-fibre carbohydrate (NFC) concentration. Recommendations based on this modelling are for a maximum of 60% FB in diets and forage supplements must provide sufficient crude protein (CP) as well as supplementation of Ca for R1 heifers and dry cows up to 21 days before calving and P for both dry cows and R1 heifers.

Ultrasound and histopathological studies of mastitis in hill-country ewes - Peterson SW; Collett MG; Kennedy EBG; Molenaar AJ; Nieper B (New Zealand Journal of Animal Science and Production, 2022)
To determine the prevalence of mastitis in hill-country ewes, 1824 mixed-age Romney ewes in one flock were examined after weaning. Ninety-one (5%) had clinical mastitis and, of these, 18 (1%) had hard udder. Defects detected by ultrasound scanning (later confirmed by gross and histopathological examination) included abscesses and fluid accumulations in gland cisterns. Four months after weaning (2-3 months after diagnosis with mastitis) udders of 57 of the 91 culled mastitic ewes, randomly selected, were examined. Teat and gland parenchyma from 50 of these were later assessed histopathologically. Common findings were abscesses involving gland parenchyma and teats, pus in teat cisterns, mucosal polyps associated with lymphocytic inflammation in teat cisterns leading to stenosis or atresia, and mild-to-moderate lymphocytic inflammation in the gland interstitium. Results indicate that a significant proportion of ewes with severe and/or permanent mastitis damage such as hard udder can be identified by palpation and ultrasound soon after weaning, but some signs, notably hard udder, had disappeared by the time of post-mortem 2-3 months later.

Use of organic waste streams to reduce the carbon footprint of New Zealand milk - Burggraaf VT; Mazzetto AM (New Zealand Journal of Animal Science and Production, 2022)
Life Cycle Assessment was undertaken to determine the impact of replacing purchased feeds and nitrogen fertiliser with New Zealand-sourced organic waste streams, on the cradle-to-farm-gate carbon footprint of a dairy farm. Five scenarios were assessed: 1) average New Zealand dairy farm, 2) supplementary feeds sourced from food waste, 3) mineral fertiliser replaced with chicken manure, 4) mineral fertiliser replaced with pig manure, 5) a combination of scenario 2 and 3. Diets in each scenario had the same total metabolisable energy and nitrogen content. Organic fertiliser was applied to ensure the same total nitrogen application per hectare. Replacing purchased feeds with waste from the food industry reduced the carbon footprint by 9%, while replacing synthetic nitrogen fertiliser with chicken or pig manure resulted in a reduction of 1%. Although this has shown the potential to reduce the carbon footprint of New Zealand milk while also reducing reliance on mineral fertilisers and imported feed, further work is required to determine feasibility and broader impacts.

BRIEF COMMUNICATION: Assessing the behaviour of pastoral poultry in an integrated system on a commercial dairy farm - Smalling SS; Greig B; Bunt C; Tanner J; Bryant RH (New Zealand Journal of Animal Science and Production, 2021)
The aim of this study was to determine the ranging behaviour and dispersal patterns of layer hens on a commercial pastoral dairy farm. One thousand seven hundred and sixty layers housed across three different flocks varying in age and shed type were observed weekly. Their outdoor area was classified into three zones based on the distance from their shed. Hens in each zone were observed for one hour at dawn, midday and dusk. There was no effect of time of day on bird dispersal patterns, but when hens were outdoors, the effect of location was significant (P<0.001) with the majority (26.77%) of hens in the apron with the remaining visible hens observed in the outer range (21.99%) and mid-range (16.33%). In integrated pastoral systems with hens, management of hen excreta dispersal can be achieved through regular relocation of housing, feeders and water. Keywords: free-range; flock; location; zones; integrated farming system

BRIEF COMMUNICATION: Changes to cow behaviour when transitioning from twice a day to a 3-in-2 milking schedule - Hall LS; Bryant RH; Edwards JP (New Zealand Journal of Animal Science and Production, 2021)
The objective of this study was to assess changes to cow behaviour when decreasing milking frequency from twice a day (TAD) to three milkings in two days (3-in-2). CowManager SensOor™ ear tags were attached to cows (n=29) for 15 days before, and 30 days after, transitioning to 3-in-2. To investigate general trends, paired t-tests were used to compare means between activity types (time spent active, highly active, not active, eating or ruminating) and milking frequency. After transitioning to 3-in-2 milking, the total time active was greater (+32.3 mins/cow/day; SEM 6.46), whilst the time spent eating (-16.2 mins/cow/day; SEM 7.57) and ruminating (-12.7 mins/cow/day; SEM 3.59) decreased. These differences were inconsistent between daylight and dark hours. These results indicate that the extra time spent in the paddock by the cows due to a 3-in-2 milking schedule was spent active, potentially due to social interaction and feed-searching behaviours, with a decrease in rumination and eating behaviours. Key words: Milking frequency; behaviour; activity; transition.

BRIEF COMMUNICATION: Investigating the pattern of lameness in dairy goats across the first two years of life - Deeming L; Beausoleil NJ; Stafford KJ; Webster J; Zobel G (New Zealand Journal of Animal Science and Production, 2021)
Lameness is a painful condition with significant welfare and economic implications. There are few data about the high-risk periods of lameness in dairy goats, therefore, the aim of this study was to evaluate how lameness occurrence changes across the first two years of life. Eighty female goats of approximately five months of age were enrolled. Gait-scoring assessments were completed at 9, 13, 17, 21 and 25 months of age. Gait scores were assigned using a 5-point gait scoring system. As there were a low number of 3, 4 or 5 gait scores recorded, a binary outcome variable was created to compare non-lame (score 1) to an impaired gait (score ≥ 2). A logistic regression (PROC GLIMMIX) was used to test if there was a difference in the proportion of goats with an impaired gait among assessments. When compared with the nine-month assessment, the odds of a goat having an impaired gait were greater by a factor of 2.15 (95% CI: 1.02 – 4.54, P<0.05) at the 13-month assessment and 3.79 (95% CI: 1.90 – 7.57, P<0.001) at the 25-month assessment; as these assessments were both following kidding events, this suggests that parturition may increase the risk of lameness in dairy goats. Keywords: gait score; uneven gait; impaired gait; parturition; welfare

Can GreenFeed automated emissions monitoring systems measure methane output from young red deer grazing pasture? - Bennett CP; Ward JF; Jonker A (New Zealand Journal of Animal Science and Production, 2021)
and validation of methane-mitigation strategies for farmed deer requires a technology that can be deployed under grazing conditions. The GreenFeed automated emissions monitoring system (GAEM) integrated with an automated concentrate feeder has been successfully used to determine methane output from cattle but has not been tested with deer. The objective of this study was to evaluate large and small ruminant GAEM units with rising-yearling red deer, to determine if they would access the feed lure, and remain for sufficient duration in the hood of the unit to collect representative measurements of methane outputs. Groups of 14 mixed-sex red deer were used in three trials during spring of 2020. In each trial, approximately a third of individuals accessed the GAEM units after being habituated to the lucerne pellet lure, more than 85% of visits were < 2 min. With further refinement of deer-training protocols and configuration of the GAEM, pasture-based methane outputs should be able to be measured for a proportion of any mob with access to the unit. Keywords: GreenFeed; red deer; methane

A comparison of the ewe reproductive performance of Romney ewes bred to Romney or Wiltshire rams and the growth of their progeny to weaning - Corner-Thomas RA; Ridler AL; Kenyon PR; Blair HT; Morris ST (New Zealand Journal of Animal Science and Production, 2021)
This study reports the results of the first cross breeding of Romney ewes with Wiltshire rams as part of a grading-up transition. Romney mixed-age ewes were bred to either Romney (n=200) or Wiltshire rams (n=349) in March 2020. Ewe breeding pattern (cycle bred), reproductive performance (pregnancy and fecundity rates) and lambing performance (lambing rate, lamb birth and weaning live weight and lamb survival) were recorded. The reproductive performance of ewes bred to either Romney or Wiltshire rams showed few differences. There were no differences (P>0.05) in pregnancy, fecundity or lambing rates of ewes bred to either Romney or Wiltshire rams although minor differences (P<0.05) in the breeding pattern were observed. Lamb live weights at birth and in mid-lactation did not differ (P>0.05) among single, twin and triplet lambs sired by either Romney or Wiltshire rams, however at weaning Romney-sired triplet lambs were heavier than Wiltshire triplets (P<0.05). At weaning, a small percentage (1.6%) of Wiltshire lambs showed early signs of fleece shedding. Combined, these results suggest that in this flock there was little impact of introducing Wiltshire rams to a mixed-age Romney ewe flock on ewe reproductive performance and the growth of the F1 progeny to weaning. Keywords: Wiltshire; Romney; reproduction; growth; shedding

Defecation behaviour reduces horse’s utilisation of pasture - Adams BR; Gee EK; Back PJ; Rogers CW (New Zealand Journal of Animal Science and Production, 2021)
Horses kept at pasture create focal areas with high-density of faeces (latrines), which under commercial conditions can account for 30% of total pasture area. This New Zealand study observed the utilisation of pasture, and establishment of lawns and roughs within one paddock, intensively grazed (semi-set-stocked) alternately by three herds of mixed-age (mature), predominately Standardbred, horses. The paddock was grazed by horses 480 of 730 days, with mean stocking density of four horses per ha (2148 kg live weight/ha). Median grazing duration was 44 days (IQR 37-47 days). The median overall pasture cover for the study period was 1114 kg DM/ha (range 496-2191 kg DM/ha), lawns was 683 kg DM/ha (range 389-1822 kg DM/ha), and roughs was 2058 (range 753-3971 kg DM/ha). There was a trend for greater post-grazing estimated pasture growth rates in roughs relative to the lawns (P=0.054). Latrine areas constituted a median 31% (IQR 24-33%) of available pasture area, with up to two faecal-piles/m2. The results of the current study suggest that intensive semi-set-stocked management promotes the establishment of easily identified latrine areas of moderate faecal-pile concentration. These data can contribute to modelling the nitrogen-holding capacity of the soil, nitrogen leaching and the efficient utilisation of pasture of grazing horses. Keywords: equine; faeces; nitrogen; pasture

Do cows with facial eczema feel pain? - Sutherland M; Huddart F; Cox NR; Cuttance E; Schütz K (New Zealand Journal of Animal Science and Production, 2021)
Facial eczema (FE) negatively influences production and welfare. One consequence of FE is reduced feed intake, which could possibly be a consequence of cows experiencing nausea or pain or both. The aim of this study was to evaluate the association of cortisol and acute phase protein (APP) concentrations (indirect measures of pain) with gamma glutamyl transferase (GGT) and bile acid concentrations (indirect measures of liver damage) in dairy cattle. Blood samples were collected from 2,080 lactating dairy cattle from seven farms that were affected by FE and located in the North Island of New Zealand. Blood samples were analysed for GGT, bile acid, cortisol and APP (serum ferroxidase (SF), serum amyloid A and haptoglobin) concentrations. Data were analysed using best subsets linear regression including farm as a factor and various other prediction variables. There was a significant positive relationship between GGT and bile acid (P<0.001, Adjusted R2=37.3%), SF (P<0.001, Adjusted R2=27.4%), and haptoglobin (P<0.001, Adjusted R2=1.9%) concentrations, but not with cortisol. The positive association between GGT concentrations and APP (SF, haptoglobin) may partly reflect the degree of liver damage caused by sporidesmin intoxication, however, it could also suggest that animals with higher GGT levels are experiencing systemic inflammation and potentially pain. Keywords: acute phase proteins; facial eczema; gamma-glutamyl transferase; inflammation; pain

Dominant mutation(s) for low fibre curvature in the wool of sheep - Scobie DR; van Koten C; Richena M; Plowman JE; Harland DP (New Zealand Journal of Animal Science and Production, 2021)
Two sires judged to have phenotypically lustrous wool as neonates were mated to ewes that did not exhibit lustre in their fleece as adults. Around half their progeny were lustrous as neonates. Wool characteristics of these progeny were measured on an optically based fibre diameter analyser (OFDA) when they were weaned and again as yearlings. There was a profound difference in mean fibre curvature (P<0.001) such that the lustrous phenotype had less curvature in both sire groups (22.8, 24.5°/mm) compared with the non-lustrous (67.5, 56.2°/mm) as lambs, and 29.8, 28.1°/mm compared with 74.1, 55.0°/mm as yearlings. Curvature of the sire groups was significantly different in concert with breed mix, Merino in one sire and Romney in the other, but only when their fleece was not lustrous. The greasy fleece of the lustrous yearlings was significantly lighter (1.8 vs 3.0 kg, P<0.05) than their non-lustrous contemporaries, while there was no significant difference in fibre diameter between the two phenotypes as lambs or yearlings. Fibre curvature is inexpensive to measure and well-defined, whereas lustre is a qualitatively assessed trait. These findings suggest “low fibre curvature” would be a more appropriate name for the trait than “lustre”. Keywords: lustre mutant; wool fibre; crimp; curvature

Effect of concurrent pregnancy on the persistency of lactation in dairy cows milked once a day - Fu Y; Peterson SW; Lopez-villalobos N (New Zealand Journal of Animal Science and Production, 2021)
Persistency of lactation is a trait of economic importance in any dairy production system. The objective was to investigate the effect of concurrent pregnancy on the persistency of lactation in a commercial herd of dairy cows milked once a day. The data set included 1962 monthly herd-test records (total 8-9 tests per cow) of milk, fat, protein and lactose yield from 219 pregnant cows and 23 non-pregnant cows of different breeds and lactation number. The records were used to model lactation curves for pregnant and non-pregnant cows using random regression with a linear model (Wilmink function). This was not an experiment initially designed to examine the effects of pregnancy on persistency of lactation in dairy cows. Rather, in the course of normal farm operations, some cows became pregnant during lactation and others did not. Pregnancy did not affect the persistency of lactation of cows milked OAD. After conception, there was no difference in total yields between the two groups, but there was a trend that pregnant cows produced lower yields of fat (P=0.0519) and lactose (P=0.0884). This difference between our results and those of previous studies was probably because our cows were only milked once a day or because the data set was not suitable for testing the hypothesis. Further study is required to investigate persistence of lactation in pregnant and non-pregnant cows milked OAD. Keywords: pregnancy; lactation persistency; cows milked once a day

Effect of farm system and milk urea phenotype on milk yield and milk composition of dairy cows in Canterbury - Bryant RH; O'Conner PO; Robic Y; Curtis J; Handcock RC; Al-marashdeh O (New Zealand Journal of Animal Science and Production, 2021)
To investigate the effect of farm system, and cow selection for milk urea nitrogen (MUN), on milk yield and milk composition, a farmlet study was carried out between October 2018 and May 2019 in Lincoln, Canterbury. A farm system with a low stocking rate and low N fertiliser input (LSR, 2.9 cows/ha) sown with a conventional ryegrass clover and plantain diverse pastures was compared with a farm system with a moderate stocking rate and moderate N fertiliser (MSR, 3.9 cows/ha) using conventional ryegrass and white clover pastures and supplementing 3 kg DM/cow/d as crushed barley grain. Each farmlet had total herd size of 40 mixed-age HF x J spring-calving dairy cows which included six cows selected solely for a high MUN or a low MUN. There was no effect of farm system on milk fat, protein or lactose content but MUN was lower in LSR compared with MSR. Milk production was also lower for LSR (466 vs 429±12.4 kg MS/cow/ha, P<0.05), owing to poorer quality diet in mid lactation. Cows selected for low MUN tended to produce less milk compared with high MUN cows (4478 vs 3987±174 kg/cow, P<0.10) though this was partially offset by increased protein content in milk of low MUN cows. Farm system and animal selection for MUN have a greater impact on milk yield than on milk composition. Keywords: Plantago lanceolata; somatic cell count; multi-species pastures;

The effect of feeding fodder beet or kale during winter on growth and behaviour of rising-one-year-old dairy heifers - Harris P; Dalley DE; Bryant RH (New Zealand Journal of Animal Science and Production, 2021)
While fodder beet (FB) has been used by the dairy industry for winter grazing over the last 10 years, there is no published information on its effect on heifer performance. Farmers have recently expressed concern regarding the suitability of fodder beet for wintering growing dairy heifers due to the low crude protein (CP) content of the FB bulb. To compare liveweight gain and grazing behaviour, 191, 9- to 12-month-old heifers at the Southern Dairy Hub were offered either FB (n=93; HFR-FB) or kale (n=98; HFR-Kale), both with pasture baleage as a feed supplement, in winter 2019. Allocations were formulated to achieve similar energy intake, but HFR-Kale were offered a higher proportion of their diet as baleage. There were no differences in apparent DM intake, but HFR-FB consumed a diet with overall lower CP (11.4%) than did HFR-Kale (13.4%). Heifers in both treatments had a similar average daily liveweight gain (0.45 ± 0.083 kg/day) but neither group achieved the 0.6 kg/day average daily gain target for heifer growth. Differences were observed in eating and ruminating behaviour between the two groups, but more research is required to validate the measurement devices used in this study for animals grazing crop. The results indicate the challenges of achieving industry-recommended growth rates over winter in heifers grazing forage crops and highlight the importance of feed testing for nutritive value to ensure nutrient requirements are being met. Keywords: Live weight; Beta vulgaris; Brassica oleracea; allocation; intake; feed quality

Effects of alternative forages on nitrate leaching under intensive sheep grazing - Maheswaran S; Cranston LM; Millner JP; Horne DJ; Hanly JA; Kenyon PR; Kemp PD (New Zealand Journal of Animal Science and Production, 2021)
There is increasing interest in the use of alternative forages to improve animal performance and reduce nitrogen (N) leaching on farms. A system-scale field trial, which included 20 hydrologically isolated drainage plots (800 m2 /plot) was carried out at Massey University’s ‘Keeble’ farm to investigate the effects of forage type on ewe and lamb performance and the quantity of N lost in drainage. Four forage types (treatments) were studied: perennial ryegrass/white clover (RGWC), plantain/WC (PWC), Italian ryegrass/WC (IRWC) and swedes (Brassica). The forage types were included as ~24% area of a self-contained farmlet, with the remaining area (~76%) being RGWC. Ewes were weighed at mating, pre-lambing and weaning, and lambs were weighed at weaning. Drainage (mm) from each plot was measured using a tipping-bucket flow meter and sub-samples of water were analysed for nitrate-N, ammonium-N and total-N losses. The forage types had no effect (P>0.05) on ewe or lamb live weight at any occasion. The average nitrate-N losses for RGWC (0.77 kg N ha-1), PWC (0.45 kg N ha-1) and IRWC (0.56 kg N ha-1) treatments did not differ (P>0.05) and was lower than the brassica treatment (6.36 kg N ha-1).

The effects of out-of-season breeding on plasma prolactin concentrations, wool production and lamb birth weight - Peterson SW; Burnham DL; Morris ST (New Zealand Journal of Animal Science and Production, 2021)
Performance of autumn- and spring-lambing ewes was compared in a year-long trial. Ewes were shorn in November and mated to lamb in May or August. Midside wool samples and plasma were collected at seven-week intervals to determine wool-growth rate, fleece characteristics, and prolactin concentrations. Autumn lambs were lighter (P<0.001) at birth and weaning (3.92±0.1; 15.6±0.7 kg) than spring lambs (5.27±0.1; 25.3±0.7 kg). Plasma prolactin concentrations were high (150 ng/ml) at mating (Dec) of autumn-lambing ewes, but low (50 ng/ml) at mating (March) of spring-lambing ewes. Both groups exhibited periparturient prolactin surges, but in autumn-lambing ewes this created high plasma prolactin concentrations during early pregnancy when plasma prolactin is usually very low. In autumn-lambing ewes, clean fleece weights (3.75±0.11 kg), midside wool growth over 345 d (374±12 mg/cm2) and fibre diameter (39.8±0.5 mm) were significantly higher (P<0.05) than those of spring-lambing ewes (3.26±0.12 kg; 331±14 mg/cm2; 38.2±0.5 mm respectively) whilst bulk and colour did not differ. Bulk was higher (P<0.05) in single-bearing ewes (21.1±0.4 cm3/g) than in twin-bearing ewes (19.2±0.7 cm3/g). It is postulated that elevated plasma prolactin concentrations (at key times) are related to seasonal differences in birth and fleece weights. Autumn lambing is beneficial for wool growth but detrimental for lamb birth weight and growth. Keywords: out-of-season lambing; sheep; prolactin; wool growth; birth weight

The effects of substituting autumn nitrogen fertiliser with gibberellic acid on feed supply and milk production - Miller ME; Edwards GR; Hague H; Bryant RH (New Zealand Journal of Animal Science and Production, 2021)
The aim of this study was to investigate the use of gibberellic acid (GA) to improve feed supply and milk yield in late lactation. A grazing study at Lincoln used 36 lactating, mixed-age, Friesian-Jersey cross dairy cows balanced over three un-replicated treatments of perennial-ryegrass and white-clover pasture treated with nitrogen (N) fertiliser as urea (50 kg N/ha), GA as ProGibb® SG (8 g GA/ha) or untreated (Control). Treatments were applied in late March 2014 and grazed over 12 days in May. There was no effect of treatment on herbage pre-grazing pasture mass (2058±6.9 kg DM/ha, P=0.20), clover (3.6±0.86%, P=0.53), ryegrass (88.0±2.33%, P=0.24) or crude protein (CP) content (17.8±1.60%, P=0.31). All milk yield components: 14.6±0.40 L/day, 1.4±0.09 kg MS/cow/day, 5.4±0.33% fat and 4.4±0.21% protein were similar among treatment groups (P=0.71, 0.14, 0.16 and 0.06, respectively). Although faecal-N content of cows on GA pasture (3.72% N) was higher (P<0.001) than cows on N-fertilised pasture (3.45% N) there was no treatment effect (P>0.05) on urinary-N content (0.4 ± 0.02% N) or N excretion in milk (101±4.4 g N/cow/d). The lack of response to GA or N fertiliser highlights the importance of timing of growth promotants for late lactation. Keywords: perennial ryegrass; white clover; urea; growth promotants; dairy cow; milk production

Evaluation of existing equations to rank methane yields of sheep fed a range of fresh forages - Jonker A; Eugène M; de Klien C; Pacheco D; Vibart R (New Zealand Journal of Animal Science and Production, 2021)
The objective of the current study was to evaluate the performance of published equations to predict CH4 yield (g CH4/kg dry matter intake; DMI) in NZ sheep fed a range of fresh forages. A database with 182 NZ sheep CH4-yield treatment means was used to validate 17 published CH4-yield prediction equations. The CH4-yield predictions were evaluated using the square root of mean-square prediction error (RMSPE) and Lin’s concordance correlation coefficient (CCC). The three prediction equations with the smallest error (<22% of RMSPE) and the only ones with moderate CCC with observed CH4 yield were all based on data from animals fed forage only. These three models predicted CH4 yield based on DMI plus dietary neutral detergent fibre, and animal body weight, feed crude protein, or feed organic matter digestibility; and they performed better than the DMI only equations that are commonly used in national greenhouse gas inventory models and on-farm accounting models . Keywords: Meta-analysis; enteric methane; model validation; fodder crops

An evaluation of the FeedSmart app for feed planning in a controlled nutrition study - Peers-Adams JL; Smith P (New Zealand Journal of Animal Science and Production, 2021)
FeedSmart is an app designed for smartphones, tablets, and computers to help farmers make instant and accurate decisions around feed management. The accuracy of the FeedSmart app was assessed in an intensive controlled nutrition trial, over two consecutive years. The objective of the trial was to compare a maintenance (M) diet to a restricted diet, 0.6 of maintenance (R), over a 55-day period in sheep. In the first year, 48 animals were split between M and R groups. In the second year, 274 ewes were divided into light (L) and heavy (H) groups, then into M and R. The FeedSmart app was used to calculate the area required for both M and R groups. Based on previous data, restricted animals were expected to lose 7.1% of their body weight over the 55-day period. The changes in year 1 M and R groups and year 2 HM and HR groups were not significantly different from the expected changes. The weight changes in the year 2 LM and LR groups were significant, but were within the errors associated with the calculations underlying the FeedSmart app. In these trials, the FeedSmart app provided an accurate tool for feed management. Keywords: FeedSmart; feed Planning; sheep; nutrition

The fate of calves born on New Zealand dairy farms and dairy farmer attitudes towards producing dairy-beef calves - Edwards JP; Cuthbert S; Pinxterhuis JB; McDermott A (New Zealand Journal of Animal Science and Production, 2021)
Dairy calves that are not required as herd replacements provide an opportunity for beef production with a relatively low environmental footprint. A telephone survey of 262 New Zealand dairy farmers was conducted in October 2020 to gain insight into current mating and calving practices, and attitudes to dairy-beef breeding and rearing calves for beef. This number of respondents provided a margin of error of ±6%. On average, per herd, 28% of calves were kept as dairy replacements, 12% were reared on-farm for beef, 15% sold for beef rearing, 35% sold to process as ‘bobby’ calves, 5% euthanised and 4% born dead or died. The largest barriers to producing more beef calves were uncertainty around their value, followed by calving difficulties with beef bulls. The main barrier to rearing more calves for beef was higher earnings for milk than for beef. However, 60% of respondents agreed that the sector should aim to decrease the number of ‘bobby’ calves. This survey provides data for the development of cross-sector initiatives to increase dairy-beef integration and the utilisation of calves. These results provide a rich description of the current state of the sector and they suggest that at least 74% of New Zealand beef production originates in the dairy industry. Keywords: dairy calf; dairy-beef; bobby calf; calf rearing; mating

Genetic parameters for urination traits and their relationships with production traits of dairy cattle grazing temperate ryegrass and white-clover pastures - Handcock RC; Box LA; Glassey C; Garrick DJ (New Zealand Journal of Animal Science and Production, 2021)
The objective of this study was to quantify genetic parameters of daily urination traits; urinary nitrogen (UN), urination volume (Uvol), urination number (Unum), average UN concentration (UNconc) and volume per urination event (VolEvent) including their genetic correlations with milk urea nitrogen concentration (MUN) and other production traits in New Zealand dairy cattle. Heritability estimates for urination traits measured on four consecutive days ranged from 0.17 to 0.35. Repeatability estimates ranged from 0.31 to 0.58, indicating that reliable prediction of urination measures would benefit from repeated measurement over a number of days. The heritability estimate for MUN was 0.29, similar to reports in the literature, whilst the estimate of repeatability (0.73) was greater than previously published values. Estimates of the genetic correlations between MUN and urination traits ranged from -0.39 to 0.41, however, due to the small number of animals in the current study, the confidence intervals were wide. The low genetic correlations may result from variation in voluntary feed intake from cow to cow that is a feature of pasture-based grazing systems. The results suggest that urination traits may be changed through selection. The low estimates of genetic correlations between MUN and urination traits suggest that MUN may not be a useful estimator of individual UN excretion in pasture-fed dairy cattle. Keywords: urine traits; milk urea

Genome-wide association study of UV-protectant ambilateral circumocular pigmentation in Hereford cattle - Jivanjia S; Koscha T; Littlejohn M; Garrick DJ (New Zealand Journal of Animal Science and Production, 2021)
Hereford cattle have a dominantly inherited white face that is characteristic of their breed. A small proportion of Hereford cattle present with regions of pigmentation around the eyes, known as ambilateral circumocular pigmentation (ACOP), which is hypothesised to provide UV-protectant properties to the underlying tissue. ACOP has been associated with reduced incidence of two diseases, bovine ocular squamous cell carcinoma, and bovine infectious keratoconjunctivitis, making it a desirable trait for selection. We conducted a genome-wide association study for ACOP in 605 American Hereford cattle using 43,789 genetic markers, and investigated the phenotypic association between face-colour and ACOP. The most highly associated variant from our genome-wide association study mapped to Chr6 g.71059814G>A and explains most of the variation for this trait. This variant falls in close proximity to the well-known coat-colour patterning gene KIT, suggesting it may be the causal gene for this trait. Our results suggest that ACOP is not directly influenced by face-colour, and may be influenced by non-additive genetic effects. These results provide an opportunity to select for Hereford cattle with ACOP, enhancing welfare, and reducing the incidence of bovine infectious keratoconjunctivitis and bovine ocular squamous-cell carcinoma. Keywords: Hereford cattle; ambilateral circumocular pigmentation; ocular squamous cell carcinoma; infectious keratoconjunctivitis; GWAS; pigmentation traits

Genomic evaluations of sheep in New Zealand - Lee AM; Newman S-AN; Dodds KG; Nilforooshan MA; Auvray B; McIntyre S; Campbell D (New Zealand Journal of Animal Science and Production, 2021)
Many New Zealand equine owners/stud managers rely on body condition to adjust feed supply for weight management, rather than objective weigh scales. This cohort observational study examined the inter-relationship of pasture supply with monthly BCS and live weight (LW) in three groups (n = 7, 8, 9) of grazing-horses of median 6/9 BCS (range 4-8). Dry-matter (DM) intake was estimated from weekly pasture mass (using rising-plate meter), monthly pasture cuts, and fortnightly LW records. Total pasture DM at the start of grazing ranged from 559 to 3511 kg DM/ha, and grazed lawns (nutritive areas) ranged from 364 to 2601 kg DM/ha. Total estimated DM offered (including hay when offered) ranged from 1.46 to 26.37 kg DM/horse/day (0.3% to 5.3% of horses LW). Within-horse maximum monthly gains and losses were 8% LW and -13% LW respectively. Median monthly BCS change was 0/9 (range -2/9 to 1/9). There was no significant association between monthly changes in LW and BCS, indicating BCS may lack the sensitivity to manage weight. During periods of reduced DMI (below estimated maintenance) there were no significant decreases in LW or BCS. These data implied that the horses may have altered transit time to improve the relative digestibility of the limited feed on offer. Keywords: horse; weight; body condition score; pasture; intake

Grazing behaviour of young cattle around faecal pats - Boom CJ; Sheath GW; Burggraaf VT (New Zealand Journal of Animal Science and Production, 2021)
Young Holstein Friesian bulls grazed four mixed-contour paddocks for a duration of three days on ten occasions between December 2002 and March 2004. For the first seven grazing events, five faecal pats on both easy- (<25o) and steep-contoured land in each paddock were selected for monitoring herbage removal during the subsequent four to five grazing events. After each day of grazing, pasture height was measured at 5-cm intervals for 50 cm from the centre of each pat. The decrease in pasture height was converted to estimates of herbage dry matter removal. For the first three grazing events following pat deposition, avoidance of grazing herbage around pats was greatest on the first day of the three-day grazing duration. The mean distance of grazing from the centre of the pats was 21, 14, 10 and 7 cm for the first to fourth grazing events following deposition. Avoidance was greatest around pats that were deposited in late spring/early summer with little difference occurring between pats located on easy or steep land. Increased grazing pressure appeared to override the natural behaviour of young cattle to avoid grazing close to faecal pats. Grazing management of young cattle should ensure residuals of at least 1500 kg DM/ha in order to minimise the grazing of herbage surrounding faecal-pat areas which are highly contaminated with parasite larvae. Keywords: cattle; grazing behaviour; faecal pats; cattle parasites

Impact of casein- versus whey-based lamb milk replacers on growth and health of artificially reared lambs - McCoard SA; Ryrie J; MacDonald T; Hea S-Y; Pacheco D; Stevens D (New Zealand Journal of Animal Science and Production, 2021)
High cost of milk proteins has driven development of cheaper whey-based milk replacer (WBMR) as an alternative to skim-milk (casein)-based milk-replacer (CBMR) for artificial-rearing of young ruminants. This study compared growth, antibiotic/anti-inflammatory use and mortality in lambs reared on either WBMR (n=138) or CBMR (n=151) in the first three weeks of rearing at commercial scale. There was a diet x rank interaction (P=0.001) whereby CBMR-fed single/twin and triplet/quad lambs had the highest average daily gain (ADG) independent of birth-rank (362 vs. 358 g/d respectively, SED=16.7) compared to WBMR-fed lambs where higher ADG was observed in triplet/quad compared to single/twin lambs (275 vs. 213 g/d respectively, SED=16.7). Males tended to have higher ADG than females (311 vs. 294, SED=9.7 g/d, P=0.064). Overall, there was a tendency for greater mortality (11% vs. 4%; P=0.055), and overall incidence rate (N/100 animal weeks) for use of antibiotics (4.43 vs. 1.27; P=0.073) and anti-inflammatories (4.59 vs. 1.59; P=0.099) in WBMR- than CBMR-fed lambs. These results highlight that CBMR under an ad-libitum milk-feeding regime supports greater ADG independent of birth-rank and reduces the incidence of disease in the first three weeks of life compared to WBMR. Furthermore, WBMR under an ad-libitum milk-feeding regime results in lower ADG of single/twin-born lambs compared to their triplet/quad counterparts. Keywords: lambs; artificial rearing; milk replacer; composition; growth; health; mortality

Impact of winter near-maintenance or non-restricted feeding on growth and intramuscular fat content of yearling rams - PL Johnson; Knowler K; Mcrae KM; Bain WE; Pile G; Craigie CR; Rowe SJ (New Zealand Journal of Animal Science and Production, 2021)
There is increased interest in genetic improvement in intramuscular fat in lamb due to its positive association with meat quality. Live-animal measures such as ultrasound or computed tomography scanning can enable genetic selection. The optimum time at which such measurements should take place is unknown. This study investigated levels of intramuscular fat in year-old rams. During the winter of 2020, ram lambs were fed on either a just-above-maintenance pasture diet (JAM) (n=119) with a target weight gain of 50 g/day, or non-restricted feeding (GAIN) (n=120) with a target weight gain of 180-200 g/day, with all rams slaughtered after 10 weeks of differential feeding. Both groups of rams were fed a ryegrass-dominant pasture. The target for the GAIN group was achieved with an average growth rate of 182±42 g/day (range 76 to 293 g/day), however, for JAM group the average growth rate was 24±64 g/day (range -212 to 126 g/day), with a third of the animals losing weight. The JAM group were split according to whether they had gained (JAM – Gain) or lost weight (JAM – Loss) for the analysis. There were differences (P<0.001) at the time of slaughter in early spring in carcass weight between groups (23.7±0.35, 19.5±0.40 and 17.0±0.47 kg for GAIN, JAM – Gain and JAM – Loss respectively). The levels of intramuscular fat were low across all groups compared to levels normally observed in 6-8-month old ram lambs and with further differences (P<0.001) between the three groups (2.1±0.08, 1.9±0.09 and 1.4±0.10 kg for GAIN, JAM – Gain and JAM – Loss respectively). More work is required to understand management systems that allow improved expression of the trait. Additionally, careful consideration needs to be given to winter grazing management of all young stock, as there is considerable variability in individual animals handling of winter maintenance feeding. Keywords: lamb; maintenance feeding; intramuscular fat

Investigating the potential for global positioning satellite data to provide information on ewe behaviour around the time of lambing - PL Johnson; Welsh A; Knowler K; Pletnykov P (New Zealand Journal of Animal Science and Production, 2021)
Global positioning satellite (GPS) devices allow spatial-temporal data sets to be generated which can describe ewe movement around the time of lambing and can potentially be linked to traits of interest, such as the timing and location of lambing events and maternal outcomes including lamb weaning weight. Collar-mounted GPS units were fitted to 25 ewes during their anticipated lambing period. Lambing timing and site were estimated based on a minimum of twice-daily checks of the ewes. Lambing and GPS data were ultimately available for 15 ewes. From the resulting data set, several traits were calculated including the average distance deviation from the central point of the three-hour time block. During the birthing event (at a resolution of hours), the ewes changed their movement behaviour and remained close to the centralised point of the three-hour block. There were significant associations among the weaning weight of the ewes’ offspring (adjusted for rearing rank) and the GPS-derived traits: ewes that were comparatively inactive produced lambs with low weaning weights. Overall, this study demonstrates the potential of GPS-derived traits to be of relevance in studies investigating ewe behaviour around and after-lambing and its impact on production outcomes. Keywords: lambing; global positioning satellites; weaning weights

INVITED REVIEW: A review of the current sheep industry in New Zealand and opportunities for change to meet future challenges - PL Johnson; Newman S-AN; Mcrae KM; van der Weerden T; Brown M; Scobie DR (New Zealand Journal of Animal Science and Production, 2021)
Like all farming systems, sheep operations face increasing economic, environmental, cultural, and social challenges, including climate change and consumer expectations about their food. Genetic improvement has the potential to help with these challenges. This review explores the importance of genetic improvement on welfare and disease traits in meeting these challenges. For all wool breeds, there is a need for traits such as being polled, having a short tail and having a bare breech and a bare belly to ensure an ethical outcome. Sheep that either seasonally lose their fleece, or do not grow wool, represent an opportunity. Predicted climate change poses significant animal-health challenges, including the internal parasite Haemonchus contortus, facial eczema, flystrike and pneumonia, that are likely to encroach on a wider geographic range. Given consumer expectations around reduced chemical inputs and improved animal welfare, genetic improvement will play a critical role in developing sheep that are more tolerant to such health challenges. While several key physical characteristics required for the future exist in minor breeds currently in New Zealand, their performance under a range of New Zealand commercial farming conditions has not been evaluated. Some overseas breeds, such as Katahdin and Barbados Blackbelly, may offer opportunities. Consideration needs to be given to the use of novel gene pools both within and outside the New Zealand sheep industry for it to be able to meet future challenges. To achieve this end, more information is needed about the overall merit of these novel breeds, to be able to identify the best strategy to take towards breeding sheep that address the future needs of the New Zealand sheep industry. Keywords: sheep; genotypes; breeding; future

Live weight and bone growth from birth to 15 months of age in pure-bred and cross-bred Jersey and Friesian heifers - Gibson MJ; Rogers CW; Hickson RE; Dittmer KE; Back PJ (New Zealand Journal of Animal Science and Production, 2021)
Live weight and liveweight gain of dairy heifers has been described in New Zealand and overseas, however, the change in stature and pattern of proximal and distal bone growth has, to date, received little attention. This study describes the proportional changes in stature with live weight, in a cohort of commercial dairy heifers (Holstein-Friesian, Jersey, and Holstein-Friesian-Jersey crossbred) from birth to 15 months of age. Comparisons of height, length, girth, and distal and proximal forelimb length (stature) revealed that at the same live weight, these parameters differed among breeds (P<0.05), however, the magnitude of the differences among breeds was consistently less than 1 cm. As heifer live weight increased, the contribution of the distal limb to increases in height decreased, which is consistent with knowledge that physeal closure in cattle occurs earlier in distal limb bones, such as the metacarpus, than in proximal limb bones, such as the humerus. In addition, the understanding of proximal and distal growth in cattle identifies when heifers are most susceptible to growth checks. Keywords: bone; stature; fracture; dairy heifer

Optimising a panel of single nucleotide polymorphisms for genomic prediction in New Zealand sheep - Lee AM; Dodds KG; Newman S-AN; Campbell D; Clarke SM (New Zealand Journal of Animal Science and Production, 2021)
A national genetic evaluation called the New Zealand Genetic Evaluation (NZGE) is undertaken weekly to support the genetic improvement of sheep via selective breeding in New Zealand (NZ). This is based on single step genomic best linear unbiased predictions (ssGBLUP), which allows animals that have genotypes and pedigree, or just pedigree, to be included in the same analysis (or evaluation). In theory, an optimal strategy is that the density and quality of SNPs used should be high enough to track all the haplotypes segregating in the population to be evaluated. Since genomic predictions have been used in NZ sheep, the content of the SNP panel used has decreased to a panel of 41K; despite that there are new SNP panels with more content available.. The effect of using this additional content and additional SNPs from an Ovine 600K chip was investigated using the trait fleece weight at 12-months. We found that a high density panel provided more accurate predictions. However, a SNP panel based on the 50K SNPs plus a relatively small subset of additional SNPs (e.g. from the 600K Chip), were as predictive as using the high density panel. We conclude that increased SNP density, beyond the 41K selected from the Ovine 50K SNP, chip will improve prediction accuracy. Our results suggest that the inclusion of SNPs from putative quantitative trait loci (QTL) may also improve prediction accuracy. However, further analyses will be helpful to distinguish the relative benefit to accuracy of increased SNP density across the genome and/or inclusion of SNPs associated with QTL. Keywords: sheep, genetics, genomics, breeding, ssGBLUP, genomic prediction

Preliminary investigations into genetic variation in distance travelled by young sheep - PL Johnson; Cullen N; Hickey SM; Knowler K; Bryson B; Hall M; Pletnykov P (New Zealand Journal of Animal Science and Production, 2021)
In pastoral grazing systems, animals need to walk to obtain nutrients (pasture) and water, however, it is also thought that the distance an animal travels is further influenced by factors including the grazing behaviour of the animal, its health status and its general motivation for moving. The purpose of this research was to investigate the repeatability and genetic variation in the trait of distance travelled for New Zealand sheep. Data were collected using global positioning satellite (GPS) collars fitted to 422 animals from three different groups of animals (Group). The animals were allowed ad libitum grazing. Progeny from 44 sires were represented in the data set. The GPS collars were fitted for up to 17 days. Given between-day variability in distance travelled depending on paddock attributes (size and feed availability) all data were scaled to a constant mean. A univariate repeated measures model was fitted to the data using ASREML, with Group fitted within the model, and day within Group fitted as the repeated measure. The heritability estimate for daily distance travelled was 0.36±0.09, with a repeatability estimate of 0.51±0.03. The results indicate that distance travelled is a repeatable trait at the individual animal level and is under moderate genetic control. Keywords: sheep; GPS; distance travelled

Seasonal variation in pasture mass offered was not associated with changes in live weight, or body condition score, in three cohorts of horses - Adams BR; Gee EK; Back PJ; Rogers CW (New Zealand Journal of Animal Science and Production, 2021)
Many New Zealand equine owners/stud managers rely on body condition to adjust feed supply for weight management, rather than objective weigh scales. This cohort observational study examined the inter-relationship of pasture supply with monthly BCS and live weight (LW) in three groups (n = 7, 8, 9) of grazing-horses of median 6/9 BCS (range 4-8). Dry-matter (DM) intake was estimated from weekly pasture mass (using rising-plate meter), monthly pasture cuts, and fortnightly LW records. Total pasture DM at the start of grazing ranged from 559 to 3511 kg DM/ha, and grazed lawns (nutritive areas) ranged from 364 to 2601 kg DM/ha. Total estimated DM offered (including hay when offered) ranged from 1.46 to 26.37 kg DM/horse/day (0.3% to 5.3% of horses LW). Within-horse maximum monthly gains and losses were 8% LW and -13% LW respectively. Median monthly BCS change was 0/9 (range -2/9 to 1/9). There was no significant association between monthly changes in LW and BCS, indicating BCS may lack the sensitivity to manage weight. During periods of reduced DMI (below estimated maintenance) there were no significant decreases in LW or BCS. These data implied that the horses may have altered transit time to improve the relative digestibility of the limited feed on offer. Keywords: horse; weight; body condition score; pasture; intake

Sheep divergently selected for methane yield showed differences in meat fatty acid composition - PL Johnson; Agnew M; Jonker A; Hickey SM; McEwan JC; Bryson B; Dodds KG; Rowe SJ (New Zealand Journal of Animal Science and Production, 2021)
The purpose of this work was to investigate whether 18-month-old rams from the methane selection lines differed in their levels of soft tissue depth over the 12th rib (GR, as a proxy of carcass fatness) intramuscular fat (IMF), and the fatty acid composition of IMF. The rumen is the site of microbial biohydrogenation of consumed plant fatty acids and synthesis of unique microbial body fatty acids. It is known that there are differences in the microbiome and fermentation characteristics of sheep selected for and against methane production (methane selection lines). When comparing the high and low lines several differences were found. Rams from low-methane-yield-selection lines tended to have lower GR (P<0.06) than those from high line rams, but there was no evidence for a difference in levels of IMF between the lines (P=0.77). There were, however, many significant differences in the fatty acid composition (as a % of total fatty acids) of the IMF between the lines. The IMF from the low-methane-yield line had a significantly (P<0.05) higher proportion of branched-chain fatty acids, and fatty acids that are associated with the early stages of the biohydrogenation pathways in the rumen, specifically conjugated linoleic acid (CLA) and C18:1 t11 but with less C18:0 stearic acid (the end product of biohydrogenation) and a significantly higher proportion of C16:1 t9 which is produced through β-oxidation of C18:1 t11. These results provide insight into how differences in sheep from the methane-yield selection line may influence the fatty acid composition of their fat. Keywords: Methane; sheep; intramuscular fat; fatty acid composition

TECHNICAL NOTE: Emissions improbable: how inappropriate use of the Global Livestock Environmental Assessment Model (GLEAM) can overestimate the emissions associated with dairy-production chains - Fletcher AJ; Sneddon NW; Hill JP (New Zealand Journal of Animal Science and Production, 2021)
In this paper we calculate the key differences between emissions estimates made using the Food and Agricultural Organisation of the United Nations (FAO) Global Livestock Environmental Assessment Model (GLEAM) and the New Zealand-specific analysis performed for the New Zealand Greenhouse Gas Inventory and the Fonterra Farm Gate Milk life-cycle analysis (LCA) that provides a proxy for all New Zealand milk production. We discovered that a wide range of factors can be responsible for more than a doubling of emissions calculated using GLEAM compared with emissions calculated using New Zealand-specific data. Such inappropriate use of GLEAM and the resulting conclusions have been used to undermine the efficiency of New Zealand production systems in publications such as Emissions Impossible. Keywords: Life cycle analysis; modelling; dairy processing

Temperament of hand-reared beef-cross-dairy cattle does not influence production traits - Martin NP; Schreurs NM; Morris ST; Lopez-villalobos N; McDade JL; Hickson RE (New Zealand Journal of Animal Science and Production, 2021)
Abstract Evaluation of temperament of calves early in life is associated with growth and meat quality in extensively farmed beef cattle. However, the relationship between temperament and performance is unclear for hand-reared beef-cross-dairy calves. This experiment analysed temperament of 1077 Angus- and Hereford-sired cattle born to dairy-breed cows and hand-reared, and evaluated the value of these measurements as predictors of growth and meat quality traits. Cattle in this study were calm, with mean exit velocity (EV) between 0.76 and 1.15 m/s from 200 d to 800 d, crush score (CS) between 1.38 and 1.79 from 200 d to slaughter (1-5 scale), and measurements were highly correlated at all ages (P<0.05). Temperament at 200 d and 400 d was not related to growth, but CS was related to growth from 600-800 d (-0.011 kg/d for a 1-point increase in CS at 600 d, P<0.05). Temperament at 800 d or before slaughter was not related to meat ultimate pH or colour score. The small variation in temperament among animals was probably the consequence of cattle being acclimatised to the presence of humans due to hand-rearing and frequent handling. Therefore, temperament is unlikely to be an issue in hand-reared beef-cross-dairy cattle and should not influence growth and meat quality traits. Keywords: Artificial rearing; beef-on-dairy; beef production; crush score; exit speed; exit velocity; flight time

Is there sire variation in seasonal liveweight gain of rising-yearling red deer? - Ward JF; Cox NR; McMahon CD; Stevens DR; Asher GW (New Zealand Journal of Animal Science and Production, 2021)
Red deer exhibit the greatest seasonal control of nutritional physiology of farmed ruminants in New Zealand, highlighted by seasonal inappetence during winter, present in all sex and age classes. Four years of data from 2048 DNA-pedigreed mixed-sex progeny of 112 sires and 1069 dams from a red deer breeding stud were interrogated to investigate the hypothesis of sire variation in growth across seasons in rising yearlings. Analysis used 17145 live weights from progeny with ≥ 4 live weights to a minimum of 300 days of age. Estimates of the weights of all animals at the same age were calculated by fittinga restricted maximum likelihood model to adjust for multiple variables and create sire best linear unbiased predictions of rising-yearling growth. Liveweight gain was examined at 11 key seasonal ages. While overall post-weaning variation in liveweight gain was low (CV = 3.6-4.7%), for seasonal periods it was higher (CV 9.2-15.5%), with the greatest variability during the winter period (CV = 15.5%). Ranking sires by the predicted proportion of gained live weight of their offspring over seasonal periods showed sire variation across different seasons. Such variation may be beneficial allowing genetic selection of animals to fit dferent farm systems.Keywords: red deer; Cervus elaphus; seasonality; growth; live weight

Volatile fatty acids (VFA) in rumen samples collected pre-feeding had a stronger relationship with methane emissions in lambs fed graded levels of forage rape than VFAs in post-feeding samples - Della Rosa MM; Janssen PH; Reid P; Sandoval E; Luo D; Pacheco D; Jonker A (New Zealand Journal of Animal Science and Production, 2021)
To investigate the effect of farm system, and cow selection for milk urea nitrogen (MUN), on milk yield and milk composition, a farmlet study was carried out between October 2018 and May 2019 in Lincoln, Canterbury. A farm system with a low stocking rate and low N fertiliser input (LSR, 2.9 cows/ha) sown with a conventional ryegrass clover and plantain diverse pastures was compared with a farm system with a moderate stocking rate and moderate N fertiliser (MSR, 3.9 cows/ha) using conventional ryegrass and white clover pastures and supplementing 3 kg DM/cow/d as crushed barley grain. Each farmlet had total herd size of 40 mixed-age HF x J spring-calving dairy cows which included six cows selected solely for a high MUN or a low MUN. There was no effect of farm system on milk fat, protein or lactose content but MUN was lower in LSR compared with MSR. Milk production was also lower for LSR (466 vs 429±12.4 kg MS/cow/ha, P<0.05), owing to poorer quality diet in mid lactation. Cows selected for low MUN tended to produce less milk compared with high MUN cows (4478 vs 3987±174 kg/cow, P<0.10) though this was partially offset by increased protein content in milk of low MUN cows. Farm system and animal selection for MUN have a greater impact on milk yield than on milk composition. Keywords: Plantago lanceolata; somatic cell count; multi-species pastures;

An association between circulating copper concentrations and gammaglutamyl transferase activity in sheep after exposure to the toxin sporidesmin - PL Johnson; Amyes NC (New Zealand Journal of Animal Science and Production, 2020)
Copper is a potent catalyst of the reaction in which sporidesmin generates damaging free radicals causing facial eczema in grazing livestock in New Zealand. This study sought to investigate whether circulating copper at the time an animal is dosed with the toxin, influenced the way the animal responds to sporidesmin and whether the action of sporidesmin on the liver in susceptible animals results in changes to circulating copper. Serum copper concentrations (CU) together with gamma glutamyl transferase (GGT) activity, an indicator of bile duct damage, were opportunistically collected on over 400 animals from nine flocks in which the animal’s tolerance to sporidesmin was commercially assessed through measuring its response to a known dose of the toxin. The association between CU concentration before the animals were dosed and natural log transformed GGT activity measured 21 days after the animals had been dosed was not significant, but there was a suggestive (P=0.06) interaction between flock and CU. There was a significant positive association between natural log transformed GGT activity and CU concentrations measured 21 days after the animals had been dosed with the toxin (P<0.0001). For some individuals, the CU concentrations approached or met copper-toxicity thresholds (above 40 μmol/L). The specific biological mechanisms causing this association remain unknown, but given the role of copper in catalysing the sporidesmin reaction and the potential of toxic copper concentrations, further research is warranted. Keywords: sheep; facial eczema; copper; gamma glutamyl transferase

Body condition scoring of sheep: intra- and inter-observer variability - Corner-Thomas RA; Sewell AM; Kemp P; Wood BA; Gray DI; Morris ST; Blair HT; Kenyon PR (New Zealand Journal of Animal Science and Production, 2020)
Body condition scoring (BCS) is a hands-on tool that farmers can use to make decisions about their animal feeding and management. BCS, however, is a subjective measure of the muscle and fat cover of the lumbar spine. Observers, therefore, may show variability in scores both across time and from other observers. This study aimed to determine the intra- and inter-observer variation of both farmers and research technicians as part of a learning exercise of a farmer-learning group based at Massey University between 2011 and 2015. Nineteen farmers and three research technicians condition scored 45 mixed-age ewes on two consecutive days. Data from both farmers and technicians were analysed to determine the intra- and inter-observer variability using a weighted kappa. The results indicate that the majority of farmers and technicians had ‘excellent’ agreement (21 of the 22 observers had kappa values greater than 0.75) between days. Similarly, among pairs of observers the agreement was also ‘excellent’ (212 of 231 comparisons had kappa values greater than 0.75). The distribution of scores that contributed to each median condition score, however, indicated that lower scores (1, 1.5 and 2) has less variability than did higher scores (2.5 or greater). These results suggest that BCS is a robust farm-management tool that can be used with a high degree of repeatability. Keywords: body condition scoring; intra-observer variability, inter-observer variability

BRIEF COMMUNICATION: Influence of birth rank on cause of lamb deaths prior to weaning - Thomson BC; Smith NB; Ward KR; Muir PD (New Zealand Journal of Animal Science and Production, 2020)
Post-mortem examinations were carried out on 1098 lambs that died between birth and weaning at 12 weeks of age to evaluate the causes of mortality in a high-fertility flock. These comprised 95% of all lamb deaths from a total of 14732 lambs born over nine years. Starvation/exposure was the biggest cause of lamb deaths (26%) followed by infection (20%), hypoxia (16%) and prenatal deaths (16%). Prenatal deaths were 18%, 12% and 10%; deaths due to hypoxia were 18%, 15% and 11% and to starvation were 28%, 26% and 12% for triplets, twins and singles respectively. There were no significant differences between birth ranks for deaths from infection. Keywords: mortality; litter size; birth rank; dystocia; starvation; prenatal; single; twin; triplet; survival; sheep

BRIEF COMMUNICATION: Meta-analysis of beef cow live weights in the mid-2000s - Thomson BC; Smith NB; Muir PD (New Zealand Journal of Animal Science and Production, 2020)
As traditional beef cows are rarely weighed, there are few quality data available on beef cow live weights. Data were collected on 12 farms between 2008/09 and 2009/10 as part of a project validating the data used in the New Zealand Agricultural Greenhouse Gas Inventory Model. Beef cow live weights were collected on both herd cows (mean 541.3 kg) and on cull cows (mean 552.6 kg). Carcass data were collected at slaughter to obtain better values for dressing-out (42.6%). Carcass data provided by Landcorp Farming Ltd indicated that their average beef cow live weights were 568 kg in 2008/09. Carcass data collected by the B+LNZ Economic Service from 8511 beef cows in 2007/08 indicated that cow live weights averaged 537 kg. An unpublished MAF Sustainable Farming Fund study reported weights for 1120 cows across 15 farms and found an average beef cow live weight of 576 kg in 2006/07. An average across all these studies suggested that beef cow weaning weights between 2006 and 2010 were around 553 kg. Keywords: beef cow; liveweight; dressing-out %

BRIEF COMMUNICATION: The behaviour of sheep around a natural waterway - Bunyaga AS; Corner-Thomas RA; Burkitt LL; Draganova I; Kenyon PR (New Zealand Journal of Animal Science and Production, 2020)
Access of cattle to waterways has been shown to be a potential cause of poor-water quality, due to nutrients and pathogens deposited via urination and defecation. In addition, cattle can pug the banks of waterways and, thus, cause sediment loss. Although government-imposed regulations to fence waterways currently only applies to dairy cattle in New Zealand, it is likely that some exclusion restrictions will apply to sheep and beef in the future. This is a concern, as there is very little research examining the behaviour of sheep around natural waterways in NZ. Video recordings were made to observe the interaction of mixed-age Romney ewes (n=40) with a natural waterway at Massey University’s hill-country farm Tuapaka. Ewe behaviour and movements were monitored continuously for two weeks using GPS devices and motion-activated trail cameras. Ewes were offered reticulated water (week 2) or were restricted from accessing the water trough (week 1). Riparian zones were accessed by some ewes (n=20) whose behaviours observed appeared to be influenced by time of day and environmental temperature. When in the riparian areas, ewes spent 68% of their time grazing, 15.9% stationary and 2.2% drinking. Access to the water trough had no effect (P>0.05) on the drinking behaviour of ewes. It was concluded that, during winter, although only a small number of sheep drank from waterways, ewes accessed riparian zones to graze. Keywords: behaviour; ewes; waterways; riparian areas

Changes in live weight and fleece characteristics during the lifetime of three breeds of New Zealand feral sheep that differ in fleece type - Sumner RMW; Scobie DR; O'Connell D; Henderson HV (New Zealand Journal of Animal Science and Production, 2020)
Live weight after joining and nine fleece characteristics were recorded throughout the lifetime of flocks of Hokonui, Campbell Island and Raglan sheep grazing at Whatawhata and Winchmore Research Centres between 1991 and 2004. The wool characteristics were measured in 585 individual wool samples collected at shearing from 90 breeding ewes sampled between one year of age and up to 12 years of age. Data on live weight, fleece weight, staple length, mean and variability of fibre diameter, fibre curvature, crimping and core bulk were analysed after adjustment for effects of grazing location and reproductive performance during the previous year. The three flocks differed in all measured characteristics, with all except live weight, mean fibre curvature and core bulk exhibiting a significant flock by age interaction. Live weight attained a maximum at six years of age, while greasy fleece weight and staple length decreased after two years of age. Core bulk decreased after three years of age. Fibre curvature decreased and time to form a crimp increased throughout the sheep’s life. Fibre diameter variability between and along fibres showed a variable age response between flocks. The three feral flocks exhibited a different age response to continuously farmed breeds. Keywords: fleece characteristics; age effects; Hokonui; Campbell Island; Raglan

Deer Industry Advance Parties: farmer groups lead practice change for improved profit - Moffat I; Asher GW (New Zealand Journal of Animal Science and Production, 2020)
The NZ deer industry’s ‘Passion2Profit’ productivity improvement programme, launched in 2013, established ‘Advance Parties’ (APs) to improve profitability among New Zealand deer farmers. Animal performance on farms was highly variable, and sometimes well below potential productivity, despite a large body of knowledge from prior research investments aimed at optimising animal performance. APs are small groups of like-minded farmers focussed on helping each other implement changes in their businesses. The benefits of these changes are disseminated to the wider deer farming community through various industry communications and regional workshops. As of December 2018, there are 27 APs, with the aim for 30 on an ongoing basis, which would involve approximately 350 deer farms. This paper describes the history, functioning and measured outcomes of APs within the New Zealand deer industry. Keywords: Deer Industry New Zealand; Passion2Profit; deer-farming practice change

Effect of breed and paddock activity on bone mass and strength in three beef cattle breeds - Bijen L; Gibson MJ; Back PJ; Hickson RE; van Knegsel A; Rogers CW (New Zealand Journal of Animal Science and Production, 2020)
There are obvious phenotypic differences among beef cattle breeds, but, to date, there are limited data on the effect of breed and pasture-based management systems on the bone mass and strength of the distal limb bone (metacarpals). The left 3rd/4th metacarpal bones were collected from a cohort of Angus (AA) (n= 17), Angus × Friesian (AF) (n=13), and Angus × Jersey (AJ) (n=13) cows aged nine years at slaughter. Prior to slaughter the cohort had been intensively monitored as part of longevity- and GPS-based paddock-activity trials. Measures of metacarpal bone mass and strength were assessed using peripheral quantitative computed tomography (pQCT) scanning at the mid-diaphysis after slaughter. Locomotion parameters, based on GPS data when grazing, were collected when four and five years old. The AA and AF cows had significantly greater slaughter weight than AJ (598±14 vs 586±18 vs 514±17 kg, P<0.01 respectively). AA cows had lower wither height than AF and AJ (1288±6 vs 1311±8 vs 1269±7 mm, P<0.01) and shorter metacarpal bone length (198±2, vs 207±2 vs 210±2 mm, P<0.05). At the mid-diaphyseal site, AF and AJ cows had greater bone mineral density (BMD)v than did AA cows (977±8 vs 1018±9 vs 1019±9 mg/cm3, respectively, P<0.001), but had less cross-sectional area (882±16 vs 816±18 vs 731±18 g/cm3, P<0.05 respectively). Across all breeds, there was a negative relationship of slaughter weight with BMDv. No significant relationships were found between distance walked on moderate and steep terrain (GPS data) and the pQCT measures. Breed influenced the size and structure of the metacarpal bone, which altered the material properties (pQCT) measured. The limited amount of high-strain-rate exercise in these cattle may explain the lack of association between locomotion data and measures of bone mass and strength. Keywords: bovine; bone; GPS; locomotion; beef

Effect of simulated spot-sampling duration and timing on the precision of methane estimation from cattle using respiration chambers - Biswas AA; Joner A (New Zealand Journal of Animal Science and Production, 2020)
The objective of the current study was to determine the precision of CH4 emission estimates from simulated spot-samples of variable time length (0.25 to 3.0 h) and over time compared to 24-h measured CH4 emissions, both based on respiration chamber data of the same day within cattle. Respiration chamber methane data, recorded approximately every 3 min, from two experiments were used, each with 12 growing beef cattle measured over two or three consecutive days. The ~3 min CH4 emissions during 24 h per animal per day were averaged in time intervals (bins; i.e. simulated spot-sample duration) of 0.25, 0.5, 1.0 and 3.0 h (expressed as g/d) from morning and from afternoon feeding. Precision of each time bin was evaluated by determining between-animal coefficient of variation (CV) and Pearson correlation (r) with 24-h measured emissions. In general, the average CV increased and the CV became more variable over time when the bin duration decreased from 3 h to 0.25 h. The correlation was low (r of approximately 0.1 to 0.5) in the first 0.5 to 2 h after the start of a feeding, after which the correlations increased (r of approximately 0.5 to 0.9) and remained relatively constant up to about 8 h after feeding. The overall trends observed suggest that the precision of a CH4 measurement improved with increasing simulated spot-sample (bin) duration from 0.25 to 3 h and the best time to take a spot-sample (based on any of the bin durations) would be between approximately 1 to 6-8 h after feeding. However, the best timing to perform spot-sampling was not fully consistent between the experiments and between emissions after morning and afternoon feeding, which warrants further investigation. Keywords: Spot-sampling; enteric methane; precision; time bin; variation

Evaluating anti-CarLA salivary IgA response in a deer progeny test - Ward JF; Wheeler M; Shaw RJ; Asher GW (New Zealand Journal of Animal Science and Production, 2020)
Farmed red deer (Cervus elaphus spp) are susceptible to infection by nematode parasites. A salivary antibody (IgA) that is naturally produced in response to exposure to a nematode parasite carbohydrate larval surface antigen (CarLA) can provide a protection against gastro-intestinal nematodes in sheep and rising-yearling farmed red deer. The concentrations of this CarLA-IgA were measured in saliva samples collected at 6 and 10 months of age, in 1531 rising-yearling progeny of 36 sires across three farms during a three-year progeny test. The CarLA-IgA concentrations differed across sires, farms and years, with 6-month levels being much lower than 10-month levels. Heritability estimates were low (h2=0.10) for 6 months, but moderate and significant (h2=0.37, P<0.05) for 10 months. These two traits were highly genetically correlated (rg=0.86) and moderately phenotypically correlated (rp=0.27). There were low (rp 0.08-0.13) but significant (P<0.05) favourable phenotypic correlations with spring and pre-slaughter live weight, and with growth rate from 3 to 10 months of age and 6 to 10 months of age. Sire variation and heritability of 10-month response indicates that it may have utility as a selection criterion for improved ability of farmed deer to cope with nematode challenge. Keywords: red deer; nematode parasite; carbohydrate larval antigen; immune; Cervus elaphus

Factors affecting early concentrate uptake by calves - Muir PD; Thomson BC; Smith NB (New Zealand Journal of Animal Science and Production, 2020)
Early solid food intake is key to a successful early rumen development system. In NZ, specialist bull-calf rearers tend to feed four-day-old calves restricted milk, ad lib pellets and wean early (5 to 6 weeks). A range of experiments examined the effect of protein %, feed form and the effect of changing protein source in older calves. There was no difference between 16% and 20% protein pellets in the first three weeks but between weeks three and six, feed intakes and liveweight gains were higher on 20% protein pellets (P<0.05). Weaning live weights were higher on a customised pellet (51.5% maize, 20.0% peas, 20.0% soy bean extract 48, 5% molasses, 1.5% limestone, 1.0% soybean oil, 0.8% salt, calf vitamin mineral premix (0.01%), Bovatec (0.006%) and Rumasweet palatant (0.00002%)) than on a commercial pellet (68.9 vs 64.8 kg, P<0.05). Feeding the customised formulation either in roller-milled, hammer-milled or pelleted form did not affect feed intake or liveweight gain. In weaned calves welladjusted to consuming concentrates, substituting a commercial meal with palm kernel significantly reduced feed intake when fed at 60% of the ration whilst copra meal substitution significantly reduced intake at 40% in calves accustomed to eating pellets. Pellet composition had a greater impact on feed intakes and growth rate than did the form in which the feed was offered. Keywords: calf; copra meal; palm kernel; protein content; artificially reared

Genetic evaluation for farm profitability in a commercial grazing dairy herd of Uruguay - Laborde D; Lopez-villalobos N (New Zealand Journal of Animal Science and Production, 2020)
The objective of this study was to develop a genetic evaluation model for farm profitability in a seasonally calving pasture-based dairy herd in Uruguay using crossbred cows. Total lactation yields of milk (MILK), fat (FAT) and protein (PROT) were calculated for each cow-lactation using the test-interval method. Somatic cell score (SCS) was calculated as the average of log2 (somatic cell count) for each cow-lactation. Mating records were used to calculate days from start of mating to conception (SMCO). Cow live weight (LWT) was recorded once per lactation. Cows were scored annually for udder depth (UD), udder support (US), front and rear teat placement (FT and RT). In total there were 4,081 lactations from 2,371 cows recorded from 2015 to 2017. The cows were the progeny of 97 sires. Breeding values (BV) for MILK, FAT, PROT, LWT, SMCO, SCS, UD, US, FT and RT were estimated with a multi-trait repeatability animal model that included the fixed effects of contemporary group (year-lactation number) and deviation from median calving date, and the random effects of animal, cow permanent and residual error. Estimates of BVs for these traits were combined in a selection index to rank cows for farm profitability. The index was calculated as I= –0.074×BVMILK +2.13×BVFAT +7.25×BVPROT –1.48×BVLWT –3.60×BVSMCO –36.84×BVSCS +30.86×BVUD +19.67×BVUS +21.10×BVFT +20.07×BVRT. The index has been used to select the best cows as mothers of future replacements, cull the cows with the lowest selection index value, and for the selection and culling of heifer replacements. Keywords: genetic evaluation; genetic parameters; selection index; Uruguay

Genetic parameters, breed and heterosis effects for conformation scores in cows milked once a day - Sneddon NW; Donaghy DJ; Lopez-villalobos N (New Zealand Journal of Animal Science and Production, 2020)
The use of conformation traits to aid selection for functional cows becomes more important as once-a-day (OAD) milking for whole or part season becomes more common. In 2013, Massey University Dairy 1 farm transitioned their mixed-breed herd milked twice-a-day (TAD) to an OAD spring-calving system. All cows on the farm were scored for 14 inspector-scored type traits and four farmer-scored traits, for a total of 1,617 lactation records over seven seasons (2013-2019, 168 to 258 cows per year). Genetic parameters, breed and heterosis effects were obtained from an animal model that included the fixed effects of year of scoring and cow age at scoring, and the covariates of proportion Holstein-Friesian, heterosis between Holstein-Friesian and Jersey, and the random effects of permanent environment of cow and random additive genetic effect of animal. Stature and live weight were found to have the greatest heritability estimates (0.46 and 0.41 respectively), while leg angle and body condition score had the lowest (0.03 and 0.04 respectively). Breed had a significant effect on all type scores, with heterosis also having significant effects; this is an important consideration with the increasing importance of type scores for cows in OAD milking systems. Jersey cows had greater front udder and udder support scores than did Holstein-Friesians (P<0.05), while Holstein-Friesians had greater stature and liveweight scores (P<0.05). From this study, genetic selection for improved udder conformation would see beneficial gains over time, whilst body condition score is heritable, would not be similarly improved. Keywords: Traits other than production; once-a-day milking; genetic parameters

Impact of the proximity of the water source on survival and growth of triplet lambs – a case study - McCoard S; Wing J; Smith T; Hea S-Y (New Zealand Journal of Animal Science and Production, 2020)
The objective of this study was to evaluate whether the provision of greater access to watering sites two weeks prior to lambing and at least one week after lambing impacts lamb survival and growth to weaning, using triplets as a model. Triplet-bearing ewes (n=206, 116-131 days gestation) were randomly allocated to either the control (one water trough/paddock) or treatment group (2-3 water troughs/paddock) balanced for ewe live weight, body condition score and stage of gestation, at a stocking density of 8.6-9.1 ewes/ha with three replicated paddocks/treatment. Lamb survival was determined via DNA parentage and lamb growth recorded at docking, weaning and at six months of age. Lamb survival (60 vs 62%, P=0.690) and lamb growth (P=0.452) did not differ between the treatment and control groups. The key finding of this study was that increasing the availability of a water supply to triplet-bearing ewes in late pregnancy and early lactation did not influence lamb survival or growth. Keywords: sheep; triplets; water; lamb survival

Impact of trait genetic gains on methane emissions from NZ beef and dairy farms - Proctor LE; Archer JA; Sise JA; Zhang X; Crowley JJ; Amer PR (New Zealand Journal of Animal Science and Production, 2020)
The objective of this study was to provide estimates of the impact of trait genetic gains on methane emissions from NZ dairy and beef farms. The effect of each trait on gross emissions (GE) and emissions intensity (EI) was modelled by estimating effects of trait changes on per-animal feed consumption and the associated methane production, per-animal production and numbers of animals in the system. In dairy, the annual gross emissions per breeding cow associated with genetic change were estimated to increase for all traits except Residual Survival and Fertility. Conversely, emission intensity values were estimated to decrease for Milk Fat, Milk Protein, Milk Solids, Residual Survival, Fertility and Body-condition Score (BCS) as genetic merit improves. In beef production, increases in genetic merit for cow mature weight, cow BCS, cow calving ease and heifer pregnancy were estimated to increase the annual gross emissions per breeding cow. Conversely, an increase in merit associated with stayability and gestation length reduced annual gross emissions per breeding cow. The effect of increasing carcase weight on gross emissions depended on whether the faster growth performance was used to slaughter the animal earlier, or to take the animal through to heavier finishing weights. Keywords: methane; emissions intensity; gross emissions; dairy; beef

Implications of using an extended lactation to change from a spring-calving to an autumncalving farm system in South Taranaki - Jarman JWM; Kay JK; Neal M; Donaghy DJ; Tozer P (New Zealand Journal of Animal Science and Production, 2020)
Recent changes to pasture-supply curves in South Taranaki, and the availability of winter milk premiums have increased farmer interest in changing from a spring-calving to an autumn-calving farm system. One approach to changing the season of calving from spring to autumn is to extend the calving interval (CI) by delaying the mating period by ~8 months, so that they next calve in autumn and undertake an extended lactation [>305 days in milk (DIM)]. A large-scale farmlet experiment was established in South Taranaki to investigate the production and reproduction responses of cows using this approach. In June 2017, 602 springcalving cows were allocated to two farmlets. In one farmlet (SPR) 301 cows were mated in October to maintain a 12-month CI spring-calving pattern. In the other farmlet (AUT, n=301 cows), mating was delayed for eight months, and cows underwent an extended lactation (mean DIM, 488; max DIM, 577) to calve next in autumn 2019. The experiment analysed two lactations for the AUT farmlet and two and a half lactations for the SPR farmlet. Across the total experimental period, milksolids (MS) production was similar between farmlets (1,194 vs. 1,174 kg MS/cow), however, cows in the AUT farmlet were fed more supplementary feed [2,371 vs. 1,951 kg dry matter (DM)/cow]. The extended lactation changed the relationship between feed supply and herd demand, which led to excessive BCS gain and ryegrass staggers for AUT farmlet cows. Further research is required to examine grazing management during extended lactations and to assess the economic implications of this approach. Keywords: autumn calving; spring calving; extended lactation

Kōura: a novel diversified product for a changing primary sector - JW Hollows (New Zealand Journal of Animal Science and Production, 2020)
Primary sector industries in New Zealand are under increasing pressure from community to produce products with lower environmental impacts, to both air and water. Contrasting these pressures is a growing world-wide demand for protein, which historically required increased intensification and associated negative environmental impacts. One area promoted for environmental mitigation is the fencing of riparian zones along waterways. The practicalities of this can create operational issues and large areas of land can essentially become non-productive for livestock and timber production. Novel solutions could provide commercial benefit from within these riparian zones. Ernslaw One Ltd. have created approximately 20 hectares of ponds along riparian edges in their Otago and Southland forests. These ponds are used to farm freshwater crayfish or kōura (Paranephrops zealandicus) in areas that would otherwise be unproductive as production forest can no longer be grown there for environmental reasons. Customers are increasingly looking for niche foods with unique provenance such as kōura. Currently the kōura industry is in its infancy but there are many groups with licence applications underway. Utilisation of these landscape units add scale and speed towards development of a viable industry with domestic and export potential. High-value novel products such as kōura demonstrate that revenue can be obtained with little environmental impact. Keywords: kōura; aquaculture; diversification; sustainable; freshwater

Liveweight gain and urinary nitrogen excretion of lambs grazing diverse (plantain, Italian ryegrass and red clover) or ryegrass-white clover pasture in autumn - Al-marashdeh O; Cook GA; Anderson FC; Meyer JPH; Logan CM; Edwards GR; Maxwell TMR (New Zealand Journal of Animal Science and Production, 2020)
The objective of this study was to investigate the effect of grazing a diverse pasture of plantain, Italian ryegrass, and red clover versus a ryegrass-white clover pasture on the liveweight gain (LWG) and urinary nitrogen (N) excretion of ram lambs over an 82- day experimental period in autumn. Eighty Coopworth ram lambs (8 months old) were allocated to two replicates of two pasture treatments (n = 20), a diverse pasture containing plantain, Italian ryegrass, and red clover (Diverse) and conventional ryegrass-white clover pasture (RGWC). Unfasted live weight (LWT) of lambs was recorded on seven occasions during the autumn experimental period. Apparent dry matter intake (DMI) was estimated as the difference between pre- and post-grazing herbage mass plus daily herbage growth. On two occasions, urine and blood samples were collected from each lamb to determine concentration of urinary N and plasma urea N (PUN). Liveweight gain (P=0.008) and feed conversion efficiency (P=0.022) were greater in Diverse than RGWC treatment (240 vs 160 g/day and 111 vs 86 g LWT per kg DMI, respectively). Urinary N and PUN concentration were similar between treatments; however, when urinary N excretion (g/d) was estimated as a function of PUN, lambs grazing Diverse pasture excreted less (P=0.003) urinary N per 100 g LWG than those grazing RGWC pasture. The proportion of N intake retained in LWG was greater (P=0.008) for lambs grazing Diverse (11.0%) than those grazing RGWC (9.0%). The results indicate that there is a potential to achieve target LWT of lambs in a shorter time and with less N loss to the environment by using a diverse mix containing plantain, Italian ryegrass and red clover in comparison to ryegrass-white clover mix in autumn. Keywords: Growing lambs; liveweight gain; urinary nitrogen; diverse pasture; ryegrass

The management of Standardbred breeding stock on commercial properties - Rogers CW; Herbst A; Langhans K; Stone R; Hirst R; Gee EK; Back PJ (New Zealand Journal of Animal Science and Production, 2020)
This paper describes the on-farm pasture management of Standardbred broodmares on commercial breeding farms in New Zealand using data collected from three studies. The pasture on offer was typically ryegrass (70% (IQR 50-70), clover (15% (IQR 15-22), and fescue (12% IQR 6-22). Other species present included cocksfoot and plantain (10% on one farm). Weed content was low at 5% (IQR 4-8). During winter, on two farms mares were break-fed on crops of kale, standing oats and Italian ryegrass. Through the year there was limited variation in the nutritive composition of the pasture with a DM of 17±0.3%, ME of 11±0.1 MJ/kg DM and crude protein of 23±0.5%. Horses were managed using a semi-set-stocked pattern (1.7 mares/ha; 2.6 weanlings/ha). Pasture DM on offer for mares ranged from 1700-2500 kg DM/ha and 2500-3000 kg DM/ha for weanlings, which were also offered ~1.5 kg/ day (as fed) of pre-mixed concentrates. To manage pasture quality and minimise the establishment of lawns and roughs, paddocks on all farms were harrowed and cross-grazed with sheep or cattle. The management system described, while similar to that of Thoroughbreds, differs with the offering of crops to mares during winter and a higher BCS of mares. Keywords: horse; pasture; Standardbred; management; mare

Milk composition and productive and reproductive performance of cows from A1 and A2 β-casein variants, milked once or twice a day - Lu Y; Hickson RE; Gedye K; Correa-Luna M; Donaghy DJ; Lopez-villalobos N (New Zealand Journal of Animal Science and Production, 2020)
Protein is an important component of milk and it plays an essential role in all living organisms. β-casomorphins-7 (BCM-7) is derived from A1 β-casein and has been implicated in some human health issues. This A1 β-casein is produced by cows with the A1A1 or A1A2 genotype, whilst cows with the A2A2 genotype produce A2 β-casein, which has not been implicated in the same human health issues. Given the potential importance of A2 milk for public health and its apparent commercial potential, selection based on the A2 genotype and its impact on production and reproduction traits should be investigated. The objective of the current study was to compare the productive and reproductive performance of dairy cows based on A2 genotype in two different dairy farms. From July 2017 to May 2018, 206 cows (including 122 A2A2 genotype; “A2 cows”) were milked once a day at Dairy 1 and 451 cows (including 217 A2 cows) were milked twice a day at Dairy 4. Records of lactation yields of milk, fat and protein, fat percentage, protein percentage, days from start of mating to conception, pregnancy rate to first service, the submission rate at 21 days and the pregnancy rate at 21 and 42 days (PR42) after the start of mating from 642 cows in two herds were analysed. The effects of A2 genotype on production and reproduction traits were not significant. The interaction between farm and β-casein genotype was significant for PR42 (P<0.05) but not for any other traits. The interactions between parity number and genotype were not significant for any of the traits. The results indicated that cows of different β-casein genotypes have similar production and reproductive performance. Keywords: β-casein genotype; A2 milk; protein percentage; pregnancy rate at 42 days

Miniature horses in New Zealand: demographics and feeding management - Goh SY; Gee EK; Thomas DG; Back PJ; Rogers CW (New Zealand Journal of Animal Science and Production, 2020)
An online survey on demographics and feeding management of Miniature horses in New Zealand was conducted using the Qualtrics Survey Software. There were 232 valid responses from respondents who kept 1183 Miniature horses, representing ~ ⅓rd of the New Zealand Miniature horse population. Miniature horses were kept for leisure and companionship (56%), competition (35%) and for breeding (7%). The majority (79%) of Miniature horses were kept at pasture on low (< 1000 kg DM/ha) to moderate (~ 2000 kg DM/ha) pasture masses across seasons. Pasture access was more commonly restricted by respondents during spring (60%), summer (60%), and autumn (55%) than in winter (43%). Most respondents (87%) practiced pasture-restriction strategies such as strip grazing, use of a paddock with little grass, and stabling/yarding. Respondents indicated the mode daily number of hours of stabling was 7-12 hours (n=57/195, 29%). The median stocking density was 10 horses/ha, (~1100 kg live weight/ha). The stocking density appeared high, however, on a live weight basis, it was comparable to the reported values in other classes of equine livestock.

A model to assess the impact of potential genetic selection of dairy cows for volume per urination and total urine volume per day on nitrogen leaching - Kennett JM; Romera A; Beukes P; Amer P (New Zealand Journal of Animal Science and Production, 2020)
The purpose of this paper is to assess the impacts of changes in herd average urine genetic traits on nitrogen (N) leaching per hectare per year. Two potential urine traits being considered for genetic selection are total volume of urine per cow per day (at constant urinary N output), and average volume per urination (at a constant daily urinary volume and N output). To understand the potential reduction in N leaching that would arise if these traits could be changed using genetic selection, a model of urine patches was developed to derive the necessary relationships between urine genetic traits, patch characteristics, and N leaching. To simulate the effect on N leaching of genetic selection the mean for each urine trait was then changed from base model values by ±10%. Increasing total urine volume per cow per day by 10% was more effective (4.5% less N leaching) than decreasing volume per urination by 10% (2.9% less N leaching). Also, selection for urine traits at higher stocking rates (four cows/ha) and higher N intake (650 g/N/day) had a lower impact on N leaching compared with lower stocking rates (two cows/ha) and lower N intakes (450 g N/day). This study showed that genetic selection for urine traits could have a positive, but limited, impact on N leaching and would be a useful tool for New Zealand dairy farmers. Keywords: Urine traits; urine patches; nitrate leaching

Persistency and lactation curves modelled using nonlinear random regression in dairy cows milked once a day - Jiang H; Hickson RE; Woods OT; Morandeau M; Burke JL; Correa-Luna M; Donaghy DJ; Lopez-villalobos N (New Zealand Journal of Animal Science and Production, 2020)
Modelling lactation curves of dairy cows is important for improved feed management and breeding decisions. The objectives of this study were to compare measures of lactation persistency obtained from the modelling of lactation curves for daily yields of milk, fat and protein using a nonlinear random regression model in dairy cows milked once a day under grazing conditions. A total of 1,955 monthly herd-test records of milk, fat and protein from 55 Holstein-Friesian (F), 64 Jersey (J), and 123 F×J crossbreds of different lactations were used to obtain lactation curves for each cow using a random regression model with the Wood function. Three measures of persistency were calculated based on ratios of yields and compared with persistency calculated based on parameters of the Wood function. Jersey cows in lactation 3 had the greatest persistency for all persistency measures. In first-lactation cows, there were no significant breed differences in persistency. Persistency measures were strongly correlated with each other (r≥0.97; P<0.001). The conclusion from this study is that parameters of the lactation curve (peak yield, day of peak and persistency) can be precisely estimated using the random regression model with the Wood function. Keywords: modelling; lactation curve; persistency; once-a-day milking

Predicting internal adipose from selected computed tomography images in sheep - PL Johnson; Juengel JL; Bain WE (New Zealand Journal of Animal Science and Production, 2020)
Dairy cattle preferentially lay down internal (INT) (e.g., kidney) adipose relative to sub-cutaneous adipose (SCF) tissue, but this pattern is the opposite in beef cattle, which preferentially deposit adipose subcutaneously. It is proposed that these differential patterns of fat distribution evolved to match the different production drivers of these breeds. As the New Zealand sheep industry has become more diverse in terms of breeds and production systems, the role that differential adipose distribution could play in supporting different production systems is of interest. The potential to use commercially obtained Computed Tomography (CT) images (i.e., six images, selected to predict carcass attributes in the live animal), to additionally predict INTF in addition to carcass fatness, was investigated using a full set (i.e., 30-32) of CT images available on 50 maternal ewe lambs. The R2 between the fulland sub-set of images for absolute amounts ranged from 0.25 for bone to 0.92 for SCF, with INTF 0.77 (P<0.001). When adjusted for total weight, correlations were slightly reduced, but still supported the ability of the analysis of the six images to accurately identify animals with differential fat distribution. Future work will include analysis of a further 550 animals from the same data set to determine the genetic correlation between the full and subset of images. If successful, adipose distribution can be predicted from existing and future commercial CT data sets and used to investigate its genetic and phenotypic relationship with production traits. Keywords: internal adipose; subcutaneous adipose; computed tomography

Relationship between body condition score and pregnancy rates following artificial insemination and subsequent natural mating in beef cows on commercial farms in New Zealand - Weik F; Archer JA; Morris ST; Garrick DJ; Hickson RE (New Zealand Journal of Animal Science and Production, 2020)
Body condition scoring is an efficient on-farm visual-assessment tool used to describe the energy reserves of animals. Cow body condition score (BCS) at crucial time points throughout the year is likely to influence reproductive performance. The aim of this experiment was to examine the influence of BCS before calving, before mating and at weaning on reproductive performance of mature beef cows. Percentage of cows conceiving to a single artificial insemination (AI) at a synchronised oestrus and pregnancy rate after 49 days of mating were determined for a total of 2,683 individual cows. Cows with a greater than average BCS had greater pregnancy rate to AI than did those with low BCS (P<0.001). The percentage of animals conceiving to AI was on average 54.8% but was lower at 42.5% for pre-mating BCS 4.5 or greater at 64.5% for BCS 9.0 (P<0.001). Cows had greater overall pregnancy rate after 49 days of mating with greater BCS; ranging from 88.3%, 75.7% and 79.7% for BCS 4.5 before calving, before mating and at weaning, respectively, to 93.5%, 93.3% and 93.3% for BCS 8.0 at the same time points. Increasing BCS up to 7 is likely to improve overall pregnancy rate, and most benefit tends to come from improving BCS in lower-conditioned cows to achieve high pregnancy results. Keywords: beef cows; BCS; reproductive performance; pregnancy rate; artificial insemination

Relationship between gamma-glutamyl transferase (GGT) concentrations and lying behaviour in dairy cattle - Sutherland M; Huddart F; Lowe G; Cox N; Cuttance E; Schütz K (New Zealand Journal of Animal Science and Production, 2020)
Facial eczema (FE) in livestock results in liver damage, impaired production and welfare, and is a significant problem in New Zealand. The pathology of this disease has been described in sheep and cattle, however, few studies have investigated the behavioural response to FE and whether behaviour can be used as an indicator of FE. Therefore, the aim of this study was to evaluate lying behaviour of dairy cattle with FE. Six farms located in the North Island of New Zealand with confirmed cases of FE were selected (n=391 lactating cows). Blood samples were collected to analyse gamma-glutamyl transferase (GGT) concentrations and three days of continuous lying behaviour were recorded using accelerometers. There was no correlation between GGT concentrations and either lying times (r2=0.0008) or lying bout frequency (r2=0.0008) when all animals were included in the analysis. In addition, lying times (means±SEM: Low: 9±0.1 h/d, High: 9±0.1 h/d; P=0.347) and lying bout frequency (means±SEM: Low: 8±0.2 no. bouts/d, High: 8±0.2 no. bouts/d; P=0.149) did not differ between pair-matched cows with Low (≤ 89 IU/L) or High (≥ 123 IU/L) GGT concentrations. Therefore, it does not appear as though lying behaviour, measured using accelerometers, is associated with GGT levels in dairy cattle. Keywords: facial eczema; gamma-glutamyl transferase; lying behaviour

REVIEW: Critiquing the relationship between body condition and animal welfare - Fisher MW; Schütz KE; Verkerk (New Zealand Journal of Animal Science and Production, 2020)
Body condition has long been used when assessing animal health and productivity, both important indicators of animal welfare; however, assessments of animal welfare must also consider the extent to which animals’ emotional needs are met. New Zealand’s codes of welfare focus on using body condition score as a measure of emaciation, requiring action to be taken at very low scores and generally recommending higher scores. In anticipation of future code reviews, the National Animal Welfare Advisory Committee is exploring our understanding of body condition as a measure of welfare, with a view to incorporating standards that also take account of animals’ affective or emotional states. Most of the scientific literature appears related to optimising animal health and production and body condition score is a good indicator of an animal’s energy reserves. While affective or emotional state may be more difficult to assess, thinner animals seem more motivated to feed as they spend more time foraging and consume more feed than ‘better’ conditioned animals. In addition, animals losing condition were more interested, anxious or excited, suggesting higher feeding motivation and possibly hunger. A more nuanced understanding is needed that considers the circumstances of the animal; what individual animals are feeling; and that body condition per se may not necessarily reflect hunger. In addition, the stage at which compromises to body condition are deemed unreasonable or unnecessary, and the reserves required in extensive environments, suggest more complex research, regulatory and non-regulatory understandings and interventions will be required. Keywords: body condition; survival; production; health; behaviour; feelings; animal-welfare standards

Seasonal effects of two forage-based nutrition regimens on intake and average daily gain of three genotypes of young red deer (Cervus elaphus) - Stevens DR; Corson ID (New Zealand Journal of Animal Science and Production, 2020)
The red deer genotypes currently being farmed in New Zealand have different forage-use habits and exhibit different growth profiles in different seasons. Three genotypes (NZ red, eastern European and elk-cross) were subjected to low and high nutritional regimens during autumn, winter and spring. Few differences among genotypes were found in autumn, but in winter the elk-cross genotype grew faster than did the NZ red and eastern European genotypes. NZ red deer consumed approximately 9% of their diet as hay in both autumn and winter, while eastern European and elk-cross deer had much higher intakes of hay (up to 44%). Divergence in response to the high- or low-nutrition regimens imposed developed in winter. Liveweight gain averaged 84 g/d on the low nutrition regimen and ranged from 132 to 199 g/d for NZ red and elk-cross genotypes respectively on the high-nutrition regimen. Eastern European deer were immediate. In spring as the NZ red genotype did not respond to increasing feed availability, while the eastern European and elk-cross deer increased growth rate by approximately 50 g/d and 100 g/d, respectively, in response to increased feed availability. This was matched by increases in forage and metabolisable energy intake. Understanding these interactions provides information that will enable feeding systems to be tailored to deer genotype to improve on-farm resource-use efficiency. Keywords: diet selection; energy; forage intake; genotype; liveweight gain; red deer; seasonality.

A survey of fodder beet use and feeding practices on dairy farms in Canterbury, Otago and Southland - Edwards JP; Dalley DE; Pinxterhuis JB; Woods RR (New Zealand Journal of Animal Science and Production, 2020)
High yields, consistent quality and emerging environmental benefits make fodder beet (FB) an important feed in South Island dairy systems. However, these benefits may be negated by animal-health issues associated with some FB-feeding regimes. To quantify the range and prevalence of feeding regimes, a telephone survey focussing on practices in 2018 was conducted in Canterbury, Otago and Southland. Of the farmers surveyed, 69% fed FB, 24% had never fed FB and 8% of farmers had stopped feeding FB. The most frequently cited reasons for having stopped feeding FB were animal-health issues, cost and management challenges. Most (82%) respondents feeding FB determined allocation by yield and break area. Almost all farmers (98%) transitioned cattle on to FB, over an average of three weeks. Of those that fed FB to non-lactating cows in winter, the mean allocation was 10.3 kg DM/cow/day (66% of the diet), and 12% fed FB ad libitum. A greater proportion of herds fed FB (41% of herds) reported metabolic issues (>5% of the herd affected) compared with herds not fed FB (23%). This survey is valuable to inform future research and reinforces the need to continue investigating animal-health issues associated with FB-feeding, with an emphasis on metabolic issues. Keywords: fodder beet; winter crop; animal health

Technical note: A comparison of editing criteria for lying-behaviour data derived from three-dimensional accelerometer devices on grazing dairy cows - Hendriks SJ; Phyn CVC; Turner S-A; Mueller KR; Kuhn-Sherlock B; Donaghy DJ; Huzzey JM; Roche JR (New Zealand Journal of Animal Science and Production, 2020)
Shorter, more-frequent lying bouts (LB) could be used to predict calving and as an indicator of animal discomfort and ill-health. In this technical study, we reviewed the literature to describe criteria for removing false short LB, caused by minor movements, from accelerometer data using IceRobotics technology. Using an existing dataset of grazing cows, we compared unedited with edited accelerometer data after applying three different LB thresholds (LB <33 s, ≤2 min, and <4 min were removed) within IceQube and IceTag accelerometers. Daily lying time, LB (no./d) and LB duration were derived from either IceQube or IceTag devices for 146 and 159 multiparous cows, respectively. Very-short LB were more common in IceTag than IceQube data. Applying a shorter LB criterion (<33 s) to the IceQube dataset produced minimal differences between unedited (8.8±3.6 no./d; n=64,512 lying records) and edited data (8.3±3.4 no./d; n=60,463). In contrast, we observed large differences between unedited (307±293 no./d; n=2,305,693) and edited data (8.8±4.1 no./d; n=66,139) when a longer LB criterion (≤2 min) was applied to the IceTag dataset. Removing short LB that are unlikely to represent true behaviour will improve the interpretation of lying behaviour data; however, prospective studies are needed to determine the most-suitable LB criterion. Keywords: lying behaviour; grazing cows; accelerometer

Trainers perceptions of the impact of different feeding and management practices on racehorses they identified displaying symptoms of recurrent exertional rhabdomyolysis - Wood LJ; Lancaster BE; Breheny MR; CW Rogers (New Zealand Journal of Animal Science and Production, 2020)
Data on the feeding and management of racehorses and the practices perceived to benefit horses displaying signs of recurrent exertional rhabdomyolysis (RER) were collected via a cross-sectional face-to-face survey of 100 registered Thoroughbred and Standardbred trainers in New Zealand (n=1,771 horses). In addition to quantitative data on feeding practices, qualitative data on trainers’ perceptions and motivations for the different feeding and management practices were also collected. Few trainers recognised that starch in the diet was associated with increased clinical signs of RER (26% of Standardbred and 13% of Thoroughbred trainers). One third of trainers (39% of SB and 34% of TB) stated that oats contributed to RER. Most trainers with RER horses (96% TB and 84% SB) provided a day off (day with no training) to these horses. Half of the trainers with RER horses (SB and TB) decreased concentrate feeds on days off for all horses and few trainers (12.5% SB and 8% TB) only decreased concentrate on days off if the horse displayed signs of RER. Most trainers had sought advice about RER management from a veterinarian or feed representative (63% SB and 78% TB). However, despite this, many of the responses indicated a lack of clarity on the feed and management factors that contribute to the risk of clinical signs of RER.

Vol 80 (New Zealand Journal of Animal Science and Production, 2020)

Association of bacterial contamination of colostrum with passive immunity and growth rates in dairy heifer calves - Back PJ; Hickson RE; Sneddon NW; Coleman LW; Laven RA (New Zealand Journal of Animal Science and Production, 2019)
Failure of passive transfer of immunity in calves is associated with poor-quality colostrum, determined by Immunoglobulin G (IgG) concentration. Another quality problem of colostrum is bacterial contamination, which can impair IgG absorption by the calf. Thirty-five samples from daily pooled first-milking colostrum collected over a period of six weeks were tested for IgG concentration and bacterial contamination. Seventeen of 35 first-milking colostrum samples (49%) had bacterial counts above a 100,000 CFU/ml threshold. Twenty-nine of the 35 pooled colostrum samples were fed to 63 newborn heifer calves, of which 12 (41%) had bacterial loads above 100,000 CFU/ml and were fed to 36 calves. Only eight samples (28%) had Brix values >22% and five samples (17%) fed to nine calves met the criteria of low bacterial load and high Brix (>22%). Twelve of the 63 calves (19%) had serum IgG concentrations <10 mg/ml so were classified as having failure of passive transfer, of which 10 of these calves were offered colostrum with high bacterial counts. However, there was no association of level of bacterial contamination with subsequent growth. There were no differences in serum IgG concentrations of calves which were fed colostrum that exceeded the quality threshold and those that were not. Calves with greater serum IgG concentrations grew faster (P<0.05).

Associations of body condition score and change in body condition score with lamb production in New Zealand Romney ewes - Tait IM; Kenyon PR; Garrick DJ; Lopez-villalobos N; Pleasants AB; Hickson RE (New Zealand Journal of Animal Science and Production, 2019)
Body condition score (BCS) is an on-farm subjective measurement used to inform feed management decisions in sheep. This study determined the associations of BCS and changes in BCS on production. Ewe BCS was recorded four times annually in a flock of 2534 Romney ewes aged one-five, first bred at eight-months of age. Production was measured as the number of fetuses scanned (NLS), number of lambs weaned (NLW), average weight of lambs weaned (WWT) and total weight of lamb weaned (TLW). Ewe BCS was greatest at lambing and lowest at weaning. At pregnancy scanning (at an average of 75 days of pregnancy), two weeks prior to lambing, and at weaning, BCS ≥4.5 was associated with the lowest NLS and NLW, but the greatest WWT. Ewes with a BCS ≤2.5 at weaning were associated with the greatest TLW, suggesting these ewes had utilised their stored body fat to achieve high milk yields. Ewes that decreased BCS between lambing and weaning produced greater (P<0.05) TLW compared with ewes which maintained or gained BCS indicating their body reserves were acting as a buffer for milk production. The results of the current study showed that there was an effect of BCS on NLS, NLW, WWT and TLW. The change in BCS from scanning to weaning is an important determinate of NLW, WWT and TLW. A further study with more focus on the change in BCS is, therefore, warranted.

Barriers to the adoption of animal welfare standards: shelter on pastoral farms - Fisher MW; Stockwell W; Hastings A; Brannigan JIE; Lyons CE; Timmer-Arends P (New Zealand Journal of Animal Science and Production, 2019)
The expectations for and provision of shelter for livestock remains a challenge. To help align expectations and recommendations, research was undertaken to determine the main barriers to the greater adoption of standards. Semi-structured qualitative interviews were undertaken with 24 New Zealand farmers and 22 animal-interest stakeholders. In addition, 700 members of the public were surveyed on-line. Shelter was seen as part of good farming, recognized in productivity and efficiency, and was part of the environmental and market demands. While some farmers considered that their shelter could be better, they had other, more-pressing, priorities. The key barriers included costs, time and resources, impacts on productivity, the provision of information and a lack of enforcement. While the public acknowledged animal welfare as important, including providing livestock with shade, shelter and a comfortable resting place, fewer thought that, in this respect, animals were provided for particularly well. It will be necessary to acknowledge the complexity of the issue borne of different animals, environments and people; and that initiatives may be better managed as part of wider social expectations.

BRIEF COMMUNICATION: A case study of the effects of diet and winter management on dairy production, profit and nitrate leaching in Rotorua - Burggraaf VT; Rennie GR; Edwards P; Pinxterhuis I (New Zealand Journal of Animal Science and Production, 2019)
Feed and winter management options were modelled for a dairy farm and its adjoining support land in the Lake Rotorua catchment. The dairy farm grew turnips, fodder beet and oats, with non-lactating cows grazing on the dry-stock unit on pasture, kale and fodder beet. Scenarios investigated were: removing crops from the dairy farm whilst either A) reducing stocking rates by 5%; B) feeding additional palm kernel expeller (PKE); C) replacing crops, PKE and pasture silage with purchased maize grain and maize silage; or D) grazing non-lactating cows on the dairy farm and reducing stocking rates by 17%. Using a milk price of $6.00/kg MS, D was the only scenario that increased profitability of the dairy farm (7%). Compared to the base scenario, nitrate leaching on the dairy farm increased for scenario D and decreased for scenarios A, B and C. When including the dry-stock unit, total N leaching was reduced by 5, 0, 13 and 15%, for A, B, C and D, respectively, compared to the base farm. These results reiterate the importance of investigating the impact of off-farm winter grazing in nitrogen-sensitive catchments.

BRIEF COMMUNICATION: Carcass characteristics and meat quality of early, mid- and late-season commercial lambs - Ye Y; Schreurs NM; PL Johnson; Corner-Thomas RA; Agnew MP; Silcock P; Eyres GT; Maclennan G; Realini CE (New Zealand Journal of Animal Science and Production, 2019)
Comparisons were made of carcass and meat quality characteristics of three groups of wether lambs (n=15/group): a composite breed slaughtered at weaning (EARLY), and at 6-8 months of age (MID) and Merino lambs slaughtered at 12 months of age (LATE). Carcass weight and eye muscle area were measured and meat quality was measured on the Longissimus thoracis (loin). All lambs had similar carcass weights (18.7-19.0 kg; P>0.05). Meat from LATE lambs had higher ultimate pH and intramuscular fat % (P<0.001) than EARLY and MID lambs. Loins from EARLY lambs had lower Chroma (P<0.01), higher eye muscle area (P<0.001) and shear force (P<0.05) and greater percentage of polyunsaturated fatty acids (P<0.001) than loins from MID and LATE lambs. Although statistical differences were observed in meat quality measurements, differences in absolute values suggest that the three production systems resulted in minor variation in meat quality.

BRIEF COMMUNICATION: Comparison of meat quality characteristics of lambs weaned at eight or 14 weeks of age grazing perennial ryegrass-white clover pasture or a plantain-clover mix - Kok JC; Schreurs NM; Cranston LM; Corner-Thomas RA; Ekanayake WEMLJ; Morris ST; Kenyon PR (New Zealand Journal of Animal Science and Production, 2019)
This study compared the meat quality of lambs grazing either perennial ryegrass-white clover pasture or a plantain-clover mix (plantain, red clover, and white clover) from eight to 14 weeks of age followed by a six-week finishing period on perennial ryegrass-white clover pasture. Ewes and their lambs were allocated to four treatments: 1) lambs weaned early (eight weeks of age) on a plantain-clover mix (EARLY), 2) lambs with dam grazing a plantain-clover mix (HERB), 3) lambs with dam grazing pasture >1200 kgDM/ha (HIGH), and 4) lambs with dam grazing pasture <1200 kgDM/ha (LOW). Following the treatment period, all lambs weighing a minimum of 35 kg were sent for slaughter and all remaining lambs were managed and finished as one mob on perennial ryegrass-white clover pasture for a further six weeks. Lambs that reached a minimum 35 kg live weight were slaughtered and meat samples from each lamb were analysed for ultimate pH, meat colour (L*, a*, b*), drip loss and shear force but, no difference was found in objective meat quality characteristics of lambs from different treatments.

BRIEF COMMUNICATION: Conventional or Albrecht-Kinsey fertiliser approach in a commercial-scale dairy farm systems comparison - Bryant RH; Zwart T; Greer G; Casey J; Solly K; Pinxterhuis I; Horrocks A; Gillespie R; Pellow R (New Zealand Journal of Animal Science and Production, 2019)
Long-standing questions around application of nutrients other than N, P and K (such as Mg and Ca), to meet either plant or soil requirements have been tested for the first time at a commercial dairy-farm-scale. Two dairy farms with similar soil type and soil management history were used to compare physical and financial productivity when the fertiliser regime followed either a conventional plant requirement approach (CON) or an Albrecht-Kinsey soil requirement approach (A-K). A longitudinal study commencing in 2012/13 included measurements of pasture and animal production, fertility and quality, and animal health. After six years there are no apparent impacts of fertiliser regime on milk yield or pasture growth, although less N fertiliser was applied on the A-K farm and this farm grew more clover. Though not statistically significant, there were more in-calf cows and fewer metabolic problems pre- and post- calving in the A-K farm system compared with the CON system. Setting up and maintaining the soils at target parameters cost more (+$532/ha fertiliser costs in the first year; +$197 in the last two years), but animal health costs were on average $56/ha/yr lower.

BRIEF COMMUNICATION: Does stocking rate of singleton ewes during lambing and lactation affect performance? - Kenyon PR; Corner-Thomas RA; Cranston LM; Morris ST (New Zealand Journal of Animal Science and Production, 2019)
The impact of singleton-ewe stocking rate (SR, 11, 13, 15 ewes ha) during lactation on ewe and lamb performance to weaning was examined over three years. Pasture mass before lambing in 2014 was considerably higher than that in both 2015 and 2016. At weaning in 2014 there was no effect (P>0.05) of SR on ewe live weight, while in 2015 and 2016, SR 11 ewes were heavier (P<0.05) at weaning than both SR 13 and 15 ewes. Lamb live weight during lactation was not affected (P>0.05) by SR in any year. Combined, these data suggest that when pasture mass is high, SR of up to 15 ewes per ha can be utilised but at lower pasture covers increasing SR will negatively affect ewe, but not lamb live weight. Farmers, therefore, need to consider carefully if they should utilise higher SR under these circumstances.

BRIEF COMMUNICATION: Does the age and sex affect meat quality in older lambs - Thomson BC; Muir PD; Smith NB (New Zealand Journal of Animal Science and Production, 2019)
During a programme which targeted late-born heavy-weight lambs supplied at 14 months of age, the question was raised about the meat quality of old-season lambs compared to traditional new-season product. In Experiment 1, short loins from 10 new season ram lambs (3.5 months of age) and 10 old-season ram lambs (14 months of age) of similar weights and grades were compared. Samples from new-season lambs scored slightly better for most characteristics (taste P<0.10, tenderness P <0.001 and juiciness P<0.03) but there was no difference in odour (P <0.60) and few tasters disliked any of the samples. In Experiment 2, short loins from 10 ewe, nine cryptorchid and nine ram older lambs with similar carcass weights were compared. There were no significant differences in eating quality between the samples from ram, ewe and cryptorchid lambs. In conclusion, differences due to age were small when carcasses were compared at the same weight and carcass fatness.

BRIEF COMMUNICATION: Effect of a fodder beet or lucerne-chaff-based diet on triplet-bearing ewe live weight, body condition score and lamb birth weight - Knol FW; Erichsen C; Jonker A; Sandoval E; Pacheco D; Hea SY; McCoard SA (New Zealand Journal of Animal Science and Production, 2019)
The objective was to determine whether a fodder-beet based diet (FB) balanced for crude protein, vitamins and minerals could support similar ewe live weight (LW), body condition score (BCS) and lamb birth weight compared to a lucerne-based diet. Triplet-bearing ewes (60-70 days gestation) were randomly allocated to a lucerne-based (65% of dry matter [DM] n=12) or FB-based (56% FB bulb; n=16) diet. Lambs were weighed two hours after birth. Ewe LW (P=0.970) and BCS (P=0.165) did not differ between treatments and there was no diet-by-day gestational age (dGA) interaction. A diet-by-dGA interaction was observed for DM intake (P=0.003) where FB-fed ewes consumed less than control ewes with advancing gestation. A diet-by-sex interaction was evident for lamb birth weight (P=0.026) where female lambs from FB-fed ewes were heavier than female lambs from control-fed ewes, with no difference between males. These results indicate that supplementing a FB-based diet with additional protein, fibre and minerals can maintain triplet-bearing ewe BCS and LW and improve female lamb birth weight compared to those born to control ewes.

BRIEF COMMUNICATION: Effect of pre-weaning milk allowance on post-weaning behaviour of heifer calves on pasture - Groenendijk ME; Lowe K; Schreurs NM; Khan MA (New Zealand Journal of Animal Science and Production, 2019)
The objective of this study was to assess how pre-weaning milk allowance influences the grazing and rumination behaviour of dairy heifers on pasture after weaning. Group-housed heifer calves (n=28) were fed milk replacer at a low-allowance (LA; 10% of initial live weight), high-allowance (HA; 20% of initial live weight), and ad-libitum (ADLIB; free access) until 93 days of age. Heifers were then given access to pasture at 100 days of age, and were observed at 101, 108, 122 and 127 days of age. At 101 days of age, LA calves spent more time ruminating than HA and ADLIB calves, and spent less time grazing than HA calves (P<0.05). The time spent on each activity in subsequent weeks was the same among treatments. This indicates that any differences in foraging and rumination behaviour caused by pre-weaning milk allowance disappeared within a few weeks after weaning.

BRIEF COMMUNICATION: Greenhouse gas emissions from New Zealand sheep-and-beef farm systems - Hutchinson KJ; Rennie GM; Vibart RE; Mercer GJK; O'Neil K; Burtt AN; Chrystal JM; Devantier B; Smiley DR; Taylor AL; Thompson BR; Wall AJ; et al. (New Zealand Journal of Animal Science and Production, 2019)
Agriculture was the single largest contributor (48.1%) to total greenhouse gas (GHG) emissions in New Zealand in 2017, and sheep and beef livestock systems contributed about 40% of these emissions. A holistic assessment of the farm-scale drivers of GHG emissions is critical to identifying opportunities to reduce emissions. We used farm-scale models to estimate feed inventories, nutrient flows and GHG emissions for 60 sheep and beef farms. The range in annual GHG emissions (methane (CH4) and nitrous oxide (N2O)) was 189 to 6,362 kg carbon dioxide (CO2) equivalents per hectare, demonstrating the diversity in sheep and beef systems. As stocking rate and animal product (wool + net carcass weight) per hectare increased, GHG emissions increased, although some farms exhibited 50% higher emissions than others with similar animal product per hectare. The variation in GHG emissions across these farms indicates there is potential to reduce on-farm GHG emissions and remain productive and profitable.

BRIEF COMMUNICATION: Impacts of live weight of ewe lambs at mating on their reproductive performance - Haslin E; Corner-Thomas RA; Kenyon PR; Morris ST; Pettigrew EJ; Hickson RE; Blair HT (New Zealand Journal of Animal Science and Production, 2019)
This experiment investigated the impacts of heavier live weight of twin-born ewe lambs at mating on reproductive performance. Romney ewe lambs (n=270) were allocated to one of two groups: ‘Heavy’ (48.0±3.8 kg), had been preferentially fed from weaning to breeding, or ‘Control’ (44.8±3.5 kg). Both groups were exposed to crayon-harnessed vasectomised rams for 68 days before breeding, and then were bred to entire Romney rams for 34 days. Crayon marks were recorded every 17 days. Heavy ewe lambs were more likely to be mated in the first 17 days of breeding (69.9% vs. 54.8%, P<0.05), mated in the entire breeding period (85.1% vs. 69.4%, P<0.01) and had a greater litter size (0.99 vs. 0.65; P<0.01) than did Control ewe lambs. Heavier live weight at mating improved reproductive performance of ewe lambs. These results emphasise the importance of an adequate live weight at breeding for reproductive success in ewe lambs.

BRIEF COMMUNICATION: Investigation of the water-soluble carbohydrates content of Plantain (Plantago Lanceolata L.) - Jiang S; Bryant RH; Jiao J; Tung R (New Zealand Journal of Animal Science and Production, 2019)
Previous research has shown that the water-soluble carbohydrates (WSC) of Plantain (Plantago lanceolata L.) leaves differ from that of many other common forages. Analytical methods used to quantify WSC may underestimate the concentration of WSC in plantain herbage. To ascertain the suitability of current method, the conventional anthrone reaction method (AR) was compared against the phenol-sulphuric acid method (PSA). The WSC of eight plantain samples and one ryegrass sample were compared using AR and PSA against high-performance liquid chromatography (HPLC). The results showed that AR greatly underestimated the WSC content of plantain compared with PSA, which was similar to HPLC (7.18%, 13.5%, 14.7% DM, respectively, P<0.001). The discrepancy between the results from AR and PSA was due to sorbitol, which was not detected using AR.

BRIEF COMMUNICATION: Meat quality of light-weight, yearling steers of dairy origin - Pike SJ; Schreurs NM; Hickson RE; Hunt JJ; Kenyon PR; Garrick DJ; Blair HT; Morris ST (New Zealand Journal of Animal Science and Production, 2019)
Loline, an alkaloid produced by Neotyphodium endophytes in pastoral grass species with potential antimicrobial properties, has several known derivatives; N-formyl loline (NFL), N-acetyl loline (NAL), N-acetyl norloline (NANL), N-methyl loline (NML), and loline base, though the availability and form during rumen fermentation and digestion is unclear. Festuca pratensis seeds either with (LOL) or without (NIL) lolines (150-200 µg/mL) were incubated in either sterile or viable rumen fluid or in either HCL/pepsin (pH 2) or water (pH 7). At 72 hours LOL in sterile rumen fluid had 23%, 26%, and 45% more NFL (P=0.05), NANL (P=0.04), and loline base (P=0.01) respectively, with 27% more total loline present (P=0.06), and 65% more NML (P=0.09) compared with LOL in viable rumen fluid. Loline tended to alter the fermentation pattern as NIL produced 11% more ammonia (P=0.07), and 5% less propionate (P=0.06) than LOL. In HCL/pepsin there were 38%, 49%, and 39% more total lolines (P=0.05), NANL (P=0.02), and NFL (P=0.04) respectively, compared with water. Rumen and abomasal digestion appear to have a small effect on loline’s form and concentration with only slight alteration to the rumen fermentation pattern. Presence of lolines had little evidence of an antimicrobial effect.

BRIEF COMMUNICATION: Relative cost of producing carcasses from dairy-origin steers slaughtered at 8 – 12 months of age in New Zealand - Hunt JJ; Tozer PR; Kenyon PR; Schreurs NM; Pike SJ; Hickson RE; Blair HT; Garrick DJ (New Zealand Journal of Animal Science and Production, 2019)
Loline, an alkaloid produced by Neotyphodium endophytes in pastoral grass species with potential antimicrobial properties, has several known derivatives; N-formyl loline (NFL), N-acetyl loline (NAL), N-acetyl norloline (NANL), N-methyl loline (NML), and loline base, though the availability and form during rumen fermentation and digestion is unclear. Festuca pratensis seeds either with (LOL) or without (NIL) lolines (150-200 µg/mL) were incubated in either sterile or viable rumen fluid or in either HCL/pepsin (pH 2) or water (pH 7). At 72 hours LOL in sterile rumen fluid had 23%, 26%, and 45% more NFL (P=0.05), NANL (P=0.04), and loline base (P=0.01) respectively, with 27% more total loline present (P=0.06), and 65% more NML (P=0.09) compared with LOL in viable rumen fluid. Loline tended to alter the fermentation pattern as NIL produced 11% more ammonia (P=0.07), and 5% less propionate (P=0.06) than LOL. In HCL/pepsin there were 38%, 49%, and 39% more total lolines (P=0.05), NANL (P=0.02), and NFL (P=0.04) respectively, compared with water. Rumen and abomasal digestion appear to have a small effect on loline’s form and concentration with only slight alteration to the rumen fermentation pattern. Presence of lolines had little evidence of an antimicrobial effect.

BRIEF COMMUNICATION: Urinary nitrogen excretion and water balance of dairy heifers fed cut plantain or perennial-ryegrass pastures - Al-marashdeh O; Judson HG; Schetelat S; Pawsey A; Edwards GR (New Zealand Journal of Animal Science and Production, 2019)
Loline, an alkaloid produced by Neotyphodium endophytes in pastoral grass species with potential antimicrobial properties, has several known derivatives; N-formyl loline (NFL), N-acetyl loline (NAL), N-acetyl norloline (NANL), N-methyl loline (NML), and loline base, though the availability and form during rumen fermentation and digestion is unclear. Festuca pratensis seeds either with (LOL) or without (NIL) lolines (150-200 µg/mL) were incubated in either sterile or viable rumen fluid or in either HCL/pepsin (pH 2) or water (pH 7). At 72 hours LOL in sterile rumen fluid had 23%, 26%, and 45% more NFL (P=0.05), NANL (P=0.04), and loline base (P=0.01) respectively, with 27% more total loline present (P=0.06), and 65% more NML (P=0.09) compared with LOL in viable rumen fluid. Loline tended to alter the fermentation pattern as NIL produced 11% more ammonia (P=0.07), and 5% less propionate (P=0.06) than LOL. In HCL/pepsin there were 38%, 49%, and 39% more total lolines (P=0.05), NANL (P=0.02), and NFL (P=0.04) respectively, compared with water. Rumen and abomasal digestion appear to have a small effect on loline’s form and concentration with only slight alteration to the rumen fermentation pattern. Presence of lolines had little evidence of an antimicrobial effect.

Can bone measures of the bovine metacarpus predict humeral bone structure? - Gibson MJ; Rogers CW; Dittmer K; Hickson RE; Pettigrew EJ; Back PJ (New Zealand Journal of Animal Science and Production, 2019)
Peak bone mass in cattle is influenced by factors prior to puberty and insufficient peak bone mass prior to the first lactation predisposes heifers to the risk of spontaneous humeral fractures. At post-mortem examination, affected heifers present with osteoporosis (reduced periosteal circumference and reduced cortical wall thickness). Due to its location, there is no cost-effective way to scan the humerus in the live animal. However, the metacarpal bones (MC3/MC4) are straightforward to scan in a live anaesthetised animal. The aim of this experiment was to determine if the metacarpal could be used to predict bone mass and material properties of the humerus. The left humerus and metacarpal bones were obtained from 57 cattle aged six weeks to eight years. Bones were scanned at the mid-diaphysis using peripheral quantitative computed tomography (pQCT), to obtain measures of bone mass and material properties (strength). Strong positive relationships were observed (R2=0.89 - 0.98, P<0.0001) for pQCT measurements of bone mass and strength. Thus, the metacarpus is a good predictor of bone content and material properties of the humerus across cattle of differing age and maturity.

Carbon footprint of two unique farms, compared with industry averages - Dynes RA; Scobie DR; Vibart RE; Rennie G; Hutchinson KJ; Taylor A; Moss RA; Dennis S; Wall A (New Zealand Journal of Animal Science and Production, 2019)
Three years of data from a North Island breeding property (Onetai) and a South Island finishing property (Highlands) were modelled in Farmax and Overseer®, to estimate production, profitability and GHG emissions. On an annual basis, each hectare of Onetai averaged more than 100 kg meat and 25 kg of fibre across three years, worth $420/ha. On Highlands, each hectare produced 200 to 327 kg of meat and 20 kg of fibre, with revenue on average $737/ha, but varying between $433/ha in a drought and almost $900/ha in better seasons. GHG emissions (in CO2 equivalents CO2-e) ranged from 3106 to 3302 kg/ha at Onetai, and from 3043 to 5067 kg/ha at Highlands. The dramatic variation on the finishing farm was due to varying numbers of store stock purchased and finished according to available forage. Industry data for similar class farms modelled using the same software averaged around 3600 kg CO2-e /ha. Similar farms ($339/ha) were less profitable than Onetai, and finishing farms were less profitable than Highlands ($467/ha). Per hectare, all farms emitted similar amounts of GHG to literature values, but study farms produced more meat and greater financial returns. Greater efficiency of production is better for the pocket and the planet.

Change in herbage nutritive value of mown and standing pasture under rotational grazing - Bryant RH; Edwards P; Thomas C; Kay J; Clement A (New Zealand Journal of Animal Science and Production, 2019)
Varying the regrowth interval, pre-graze herbage mass and mowing pasture prior to grazing are strategies used to try to improve pasture quality and nutrient availability to grazing livestock. This study compared the nutritive value of pastures which had been mown before grazing, or grazed as standing pastures following a long (Long, 28 days) or moderate (Mod, 21 days) regrowth interval. Nutritive value and dry matter percent were determined at 0, 1, 2, 3, 4, 6, 12 and 24 hours in replicated paddocks during a 24-hour grazing period following allocation to dairy cows at 0700 h. Due to previous grazing management, which maintained a high proportion of leafy material in the grazed stratum, the nutritive value of the available herbage before grazing was similar for all treatments. Mowing before grazing resulted in a relatively constant nutrient supply over a 24 h grazing period; however, this did not alter cow performance (e.g., milksolids production or BCS) compared with grazing standing pasture. By contrast preferential selection of higher quality pasture by cows grazing standing pasture resulted in lower concentration of herbage crude protein (P<0.05) and greater concentration of fibre (P<0.05) at the end of the grazing period. When pastures were mown, herbage wilted, increasing DM from 17.5 to 39.4% DM within 24 hours (P<0.05). Despite large differences in pasture management, extending the regrowth interval and using repeated pre-graze mowing did little to alter herbage nutritive content.

Characterisation of the nutritional composition of plant components of a herb-clover mix during November to May in New Zealand - Ekanayake WEMLJ; Corner-Thomas RA; Cranston LM; Hickson RE; Kenyon PR; Morris ST (New Zealand Journal of Animal Science and Production, 2019)
Animal performance on herb-clover mixes (containing plantain, chicory, red clover and white clover) can be inconsistent. Potentially this could be due to variation in botanical and nutritional composition of plant components affecting animal selectivity and, thus, performance. Herbage samples were collected monthly from November 2016 to May 2017, from 3 paddocks located at Massey University’s Keeble farm, Palmerston North, New Zealand. Quadrat-cut samples were used to determine the herbage mass and botanical composition. Hand-plucked samples of each plant components were analysed for the nutritional composition. The botanical composition of the herb-clover mix differed over time (P<0.05). The percentage of chicory stems increased (9.2 to 16.2%) and plantain stems decreased (14.7 to 1.0%, P<0.001). Overall, the crude protein and metabolisable energy of white clover, red clover, plantain and chicory leaves were higher (P<0.05) than those of plantain and chicory stems in each month except in November. These data indicate that a higher proportion of chicory and plantain stems in a herb-clover mix would reduce overall metabolisable energy and crude protein. This information can be useful for farmers to manipulate both the botanical and nutritional composition of herb-clover mix to optimise animal performance.

Circadian variation in methane emissions by cattle and correlation with level and composition of ryegrass-based pasture eaten - Biswas AA; Jonker A (New Zealand Journal of Animal Science and Production, 2019)
The objective of the study was to determine the circadian variation in CH4 emission from cattle fed ryegrass-based pasture offered in two meals a day and identify factors that affect this circadian variation. Methane emission data (expressed as g/d) of 15 respiration chamber trials with growing beef cattle (six trials) or non-lactating (three trials) and lactating (six trials) dairy cows was analysed. Minimum CH4 production rate, measured approximately every 3 minutes, in the 24 h day, among the 15 trials ranged from 51 g/d to 217 g/d, and maximum CH4 production rate ranged from 152 g/d to 471 g/d. The ratio of maximum to minimum CH4 production rate, indicating absolute circadian variation, among the 15 trials, ranged from 1.8-fold to 4.4-fold. This ratio correlated negatively with feeding level (r =- 0.57; P < 0.05) and within the growing and non-lactating cattle dataset, the ratio also correlated negatively with forage neutral and acid detergent fibre concentration (r = -0.74; P < 0.10) and positively with crude protein concentration (r = 0.77; P < 0.10). In summary, the magnitude of circadian variation in CH4 emissions decreased with increasing feeding level over the whole dataset and also with changing pasture composition within the growing and non-lactating animal dataset.

Deterministic modelling of nitrogen utilisation by horses managed under pasture-based, intensive and semi-intensive systems with different levels of pasture intake. - Chin YY; Back PJ; Gee EK; Rogers CW (New Zealand Journal of Animal Science and Production, 2019)
There are limited data on the average nitrogen (N) intake and N loss for the different classes of equine livestock, and the different equine production systems within New Zealand. Using a deterministic model, the total nitrogen excreted, and nitrogen partitioned into animal requirements, urine and faeces were estimated based on the crude protein requirement, digestible crude protein intake, and crude protein excreted in urine and faeces. Separate models were generated for five different livestock classes managed within three different production systems (commercial breeding farm, sport horse and racehorse). Overall, the N in diet (%), the modelled daily N intake and N losses varied with the percentage of pasture in the diet. The faecal N loss remained consistent (20-25%) across diets and horse classes whereas urinary N loss increased with daily N intake and percentage of pasture in the diet. Total N loss per day was estimated to be 0.18, 0.28, and 0.48 g N/kg body weight in racehorse, sport horse and Thoroughbred mares respectively. The N excretion per unit weight from young horses, racehorses and sport horses were substantially lower than that reported for ruminants. Therefore, horse-specific data should be used when modelling farm-level nitrogen excretion.

Effect of genetic merit for milk urea on milk production and efficiency of crude protein utilization of grazing cows with contrasting supplement inclusion - CorreaLuna M; Donaghy DJ; Kemp PD; Schutz MM; Lopez-villalobos N (New Zealand Journal of Animal Science and Production, 2019)
Milk urea (MU) has been proposed as a predictor of nitrogen excreted through urine into the environment. The objective of this study was to evaluate milk production performance and efficiency of crude protein utilization (ECPU) of cows with low and high MU breeding values (MUBV) in grazing conditions with two levels of dietary supplementation inclusion. From July 2016 to May 2017, 257 cows were milked once daily with low supplementation (LS; 366 kg/cow/lactation) and 210 cows were milked twice daily with high supplementation (HS; 2,091 kg/cow/lactation). Cows within each herd were ranked as low, intermediate, or high for MUBV. The dataset consisted of 2,318 records of milk production collected from monthly herd-tests of both herds; and 853 additional milk samples obtained at early, mid and late lactation to measure MU. The ECPU was calculated as the proportion of protein yield (PY) with respect to crude protein intake (CPI); with CPI derived from feed intake estimates based on energy requirements. Cows with HS had superior milk yield (MY) and milk solids yield (MSY) [MSY= PY + fat yield (FY)] (P<0.001). Feed intake was less in LS (P<0.001) but CPI was superior compared to HS. The ECPU was better in HS (P<0.001) because of higher PY (P<0.001) along with lower CPI (P<0.001). Levels of MU were superior for LS because of higher CPI. Cows with low-MUBV had significantly lower MU along with less total daily excretion of MU during the lactation (P<0.001). Irrespective of supplementary feed level, cows with low-MUBV had less MY (P<0.001). Low-MUBV did not result in improved ECPU for either supplementary feed level: under LS, ECPU was inferior in cows of low-MUBV (P<0.001), and this was explained by reduced PY (P<0.001).

The effect of herbage type prior to fasting on the rate of liveweight loss during fasting in ewe lambs - Semakula J; Corner-Thomas RA; Morris ST; Blair HT; Kenyon PR (New Zealand Journal of Animal Science and Production, 2019)
Animal performance on herb-clover mixes (containing plantain, chicory, red clover and white clover) can be inconsistent. Potentially this could be due to variation in botanical and nutritional composition of plant components affecting animal selectivity and, thus, performance. Herbage samples were collected monthly from November 2016 to May 2017, from 3 paddocks located at Massey University’s Keeble farm, Palmerston North, New Zealand. Quadrat-cut samples were used to determine the herbage mass and botanical composition. Hand-plucked samples of each plant components were analysed for the nutritional composition. The botanical composition of the herb-clover mix differed over time (P<0.05). The percentage of chicory stems increased (9.2 to 16.2%) and plantain stems decreased (14.7 to 1.0%, P<0.001). Overall, the crude protein and metabolisable energy of white clover, red clover, plantain and chicory leaves were higher (P<0.05) than those of plantain and chicory stems in each month except in November. These data indicate that a higher proportion of chicory and plantain stems in a herb-clover mix would reduce overall metabolisable energy and crude protein. This information can be useful for farmers to manipulate both the botanical and nutritional composition of herb-clover mix to optimise animal performance.

Effect of in-vitro ruminal fermentation and HCL/pepsin digestion on loline - Froehlich KA; Greer A; Bryant RH (New Zealand Journal of Animal Science and Production, 2019)
Loline, an alkaloid produced by Neotyphodium endophytes in pastoral grass species with potential antimicrobial properties, has several known derivatives; N-formyl loline (NFL), N-acetyl loline (NAL), N-acetyl norloline (NANL), N-methyl loline (NML), and loline base, though the availability and form during rumen fermentation and digestion is unclear. Festuca pratensis seeds either with (LOL) or without (NIL) lolines (150-200 µg/mL) were incubated in either sterile or viable rumen fluid or in either HCL/pepsin (pH 2) or water (pH 7). At 72 hours LOL in sterile rumen fluid had 23%, 26%, and 45% more NFL (P=0.05), NANL (P=0.04), and loline base (P=0.01) respectively, with 27% more total loline present (P=0.06), and 65% more NML (P=0.09) compared with LOL in viable rumen fluid. Loline tended to alter the fermentation pattern as NIL produced 11% more ammonia (P=0.07), and 5% less propionate (P=0.06) than LOL. In HCL/pepsin there were 38%, 49%, and 39% more total lolines (P=0.05), NANL (P=0.02), and NFL (P=0.04) respectively, compared with water. Rumen and abomasal digestion appear to have a small effect on loline’s form and concentration with only slight alteration to the rumen fermentation pattern. Presence of lolines had little evidence of an antimicrobial effect.

Effects of maternal bromocriptine and melatonin treatments during early gestation on fetal lamb growth - Peterson SW; Wigati S; Jenkinson CMC (New Zealand Journal of Animal Science and Production, 2019)
Lower birth weights of autumn-born than of spring-born lambs may be due to a seasonal impairment of placental development, established by d84 of gestation, and perhaps mediated by high summer prolactin concentrations. This study attempted to determine whether reducing circulating summer prolactin concentrations in ewes during early gestation, using bromocriptine and melatonin, would improve placental and fetal growth and birth weights of autumn-born lambs. Pregnant mixed-age Romney ewes were randomly allocated to three treatment groups, balanced for age, live weight (LW) and source flocks, on d15 after mating. Ewes in the Bromocriptine group (n=20, LW 58.3±6.7 kg) were injected with 50 mg Parlodel®LA, the Melatonin group (n=20, LW 58.6±6.6 kg) each received one 18-mg Regulin® implant, while the Control group (n=21, LW 58.5±5.8 kg) was injected with saline solution (0.9% NaCl). At d139 of gestation, ewes were randomly allocated to a ‘Slaughter group’ sacrificed at d140-2 (n=30 LW 61.2±5.6 kg) and a ‘Live-birth group’ (n=31, LW 60.0±7.1 kg). Maternal plasma prolactin concentrations were significantly reduced by both bromocriptine (Control vs. Bromocriptine): 48.3±9.2 vs. 0.7±9.9 ng/ml (P<0.001) at d20 of gestation, and 82.6±8.5 vs. 4.5±9.1 ng/ml (P<0.001) at d40 of gestation, and melatonin treatments (Control vs. Melatonin): 82.6±8.5 vs. 18.4±9.5 ng/ml (P<0.001) at d40 of gestation, and 16.8±3.7 vs. 2.9±4.2 ng/ml (P<0.05) at d60 of gestation. Fetal plasma prolactin concentrations were not affected by treatments (Control vs. Bromocriptine vs. Melatonin): 32.4±18.3 vs. 32.4±19.1 vs. 59.8±16.4 ng/ml. At d140 of gestation, there were no treatment effects (adjusted for sex and litter size) on fetal weight, crown-rump length, placental parameters, and maternal and fetal organ weights, except thymus reduced 20% (P<0.05) by melatonin treatment. Birth weights and subsequent growth rates were similar among groups. Despite treatments reducing plasma prolactin concentrations there was no affect on placental or fetal growth, indicating that high prolactin concentrations early in pregnancy are not responsible for low birth weight in ewes lambing in May.

Estimates of genetic parameters for lactation curves for milk, fat, protein and somatic cell score in New Zealand dairy goats - Scholtens MR; Lopez-villalobos N; Garrick DJ; Blair HT; Lehnert K; Snell RG (New Zealand Journal of Animal Science and Production, 2019)
There are limited data on the average nitrogen (N) intake and N loss for the different classes of equine livestock, and the different equine production systems within New Zealand. Using a deterministic model, the total nitrogen excreted, and nitrogen partitioned into animal requirements, urine and faeces were estimated based on the crude protein requirement, digestible crude protein intake, and crude protein excreted in urine and faeces. Separate models were generated for five different livestock classes managed within three different production systems (commercial breeding farm, sport horse and racehorse). Overall, the N in diet (%), the modelled daily N intake and N losses varied with the percentage of pasture in the diet. The faecal N loss remained consistent (20-25%) across diets and horse classes whereas urinary N loss increased with daily N intake and percentage of pasture in the diet. Total N loss per day was estimated to be 0.18, 0.28, and 0.48 g N/kg body weight in racehorse, sport horse and Thoroughbred mares respectively. The N excretion per unit weight from young horses, racehorses and sport horses were substantially lower than that reported for ruminants. Therefore, horse-specific data should be used when modelling farm-level nitrogen excretion.

Estimation of heritabilities for milk urea and efficiency of crude protein utilization by day of lactation in a New Zealand dairy cow herd - Ariyarathne HBPC; CorreaLuna M; Blair HT; Garrick DJ; Lopez-villalobos N (New Zealand Journal of Animal Science and Production, 2019)
The objective of this study was to estimate the heritability (h2) of milk urea (MU) and the efficiency of crude protein utilization (ECPU) in grazing dairy cows. Data consisted of 1,866 herd-test records for MU and ECPU from 380 cows. Genetic parameters for traits were estimated using a random regression test-day model (RRM). Herd-test date and parity had a significant effect on MU and ECPU suggesting that improvement of the traits can be made through management practices. Estimates of daily h2 ranged from 0.25 to 0.49 for MU and 0.02 to 0.41 for ECPU. The highest h2 estimates for both traits were found during late lactation. Genetic improvement of MU and ECPU should consider the genetic potential to change the lactation curves of these traits and their correlation with other productive and reproductive traits.

Farm-management tools: reasons for the decision not to use specific tools - Corner-Thomas RA; Kenyon PR; Morris ST; Ridler AL; Hickson RE; Greer AW; Logan CM; Blair HT (New Zealand Journal of Animal Science and Production, 2019)
There are a large number of management tools available to farmers, however, some are utilised by only a small percentage. The reasons behind the choice not to use a particular tool were investigated using a postal questionnaire that was distributed to all New Zealand sheep farmers in 2014. Farmers were asked first to indicate from a list of 40 farm-management tools those they had used in the previous three years. For tools they had not used, they were asked to select one from a list of eight reasons. A total of 1659 usable questionnaires were received. The most commonly cited reason for not using any given tool was “not relevant to my situation” (50.3%) followed by “benefits not apparent” (15.3%) and “it’s an unwanted complication” (15.0%). Demographic factors (age, education, gender, farm type and flock size) influenced the reasons for non-use of 20 of the 22 tools. Reasons for non-use of fecundity-boosting vaccine or quarantine treatment for footrot were not influenced (P>0.05) by any demographic factors. The results suggest that although many farmers do not see the relevance of particular tools to their enterprise, demographic factors can influence their reasons for not using a tool.

The feeding and management of Thoroughbred and Standardbred Racehorses displaying clinical signs of recurrent exertional rhabdomyolysis - Wood IJ; Lancaster BE; Rogers CW (New Zealand Journal of Animal Science and Production, 2019)
Data on the feeding and management of racehorses and the prevalence of trainer-identified recurrent exertional rhabdomyolysis (RER) were collected via a cross-sectional face-to-face survey of 100 registered Thoroughbred and Standardbred trainers (n=1,771 horses). Data were collected on the number of horses in full work, number displaying signs of RER, gender, and age (≤ 3 or > 3 years), amount and type of forage available, and weights of all forages and concentrates. The estimated crude RER prevalence was 8.4% (95% CI 7.2-10.8%) with no significant difference in prevalence between breeds. Premixed feeds were fed to 98% (1,742/1,771) of the total population, and 99% (148/149) of the horses that displayed signs of RER. Feeds specially formulated for horses that “tie-up” were fed to 50% (75/149) of horses displaying RER signs. However, 64% (48/75) of these had additional grain, or a standard racing feed, included in the diet. Average starch levels (% of DE) provided to horses displaying signs of RER were 33.4±1.1%. Only 7% (11/149) of horses displaying signs of RER were provided with dietary starch levels at the recommended allowance (< 20% of DE).

Growth and milk production of dairy heifers born to two-year-old or mixed-age dams - Handcock RC; Lopez-villalobos N; Back PJ; Hickson RE; McNaughton LR (New Zealand Journal of Animal Science and Production, 2019)
Keeping replacement heifers that were the progeny of primiparous cows mated by artificial insemination, enhances rates of genetic gain. Heifers that were the progeny of primiparous cows were lighter at birth and grew at a slower rate to first calving compared with heifers born to multiparous dams. Heifers that were heavier before first calving produced more milk than did lighter heifers. This study aimed to determine if there were liveweight (LWT) or milk-production disadvantages for heifers born from primiparous compared with multiparous dams. Data comprised of LWT records from 189,936 New Zealand dairy heifers. Dams were allocated to four groups according to their age: two (2yo; n=13,717), three (3yo; n=39,258), four to eight (4-8yo; n=120,859) and nine years old or greater (≥9yo; n=16,102). Heifers born to 2yo dams were lighter (P<0.01) from three to 21 months of age than heifers born to 3yo and 4-8yo dams. The progeny of 2yo and 3yo dams produced similar milksolids yields during their first lactation (304.9±1.6 and 304.1±1.5 kg, respectively), but more (P<0.01) than that of 4-8yo dams (302.4±1.5) and ≥9yo dams (P<0.001; 297.8±1.6 kg). Heifers born to 2yo dams were lighter but produced more milk than heifers from older dams.

INVITED PAPER: Has progress been made in increasing the eco-efficiency of livestock systems? - Mackay AD; Scobie DR; Rhodes TR; Devantier B (New Zealand Journal of Animal Science and Production, 2019)
Current challenges for New Zealand livestock farming systems include soil erosion, water quality, greenhouse gases (GHG), and indigenous biodiversity. Industry data were used to quantify changes in emissions of the major livestock sectors from 1990, by examining inputs (e.g., livestock numbers, fertiliser) and outputs (e.g., GHG, nitrate leaching (N), saleable products) using Overseer. Productivity gains were significant for extensive sheep and beef farms, from 107 (meat + wool) kg/ha in 1990 up to 167 kg/ha in 2012. Gains were modest for intensive sheep and beef farms in this period (from 219 up to 238 kg/ha). Extensive sheep and beef increased from 3370 to 3997 kg/ha of GHG and N leached from 12 to 14 kg/ha. Intensive sheep and beef farm systems showed negligible change in N leached, while GHG emissions rose from 4167 to 4470 kg CO2-e/ha. North Island dairy farms increased from 672 to 1000 kg milk solids/ha, from 11341 to over 12000 kg CO2-e/ha of GHG and N leached increased from 44 up to 50 kg/ha. All farm systems delivered more product in proportion to GHG and N per hectare per year. Potential scenarios for the sheep and beef sector into the future were investigated, by examining the influence of ongoing increases in reproduction of ewes, lamb growth, hogget lambing and moving away from breeding cows and older cattle could have on future productivity gains and environmental impact. With the area in pasture likely to continue to decline in extensive livestock systems as outstanding environmental issues are addressed, the potential exists to offset > 20% of livestock GHG emissions. Intensive systems have fewer opportunities to make production and eco-efficiency gains, with less scope to reduce their impact.

Livestock and pasture management on commercial Thoroughbred breeding farms: implications for estimating nitrogen loss - Chin YY; Back PJ; Gee EK; Rogers CW (New Zealand Journal of Animal Science and Production, 2019)
Published data on livestock and pasture management on Thoroughbred breeding stud farms were collated to model and estimate farm-level variables required to estimate nitrogen leaching. On commercial farms, stocking density doubled during the breeding season (August – December). The effective stocking density increased with farm scale (number of resident mares) but decreased with farm size (total effective area). Therefore, farm nitrogen output may fluctuate seasonally and will be influenced by farm size and scale. Farm size and scale independently affected the stocking and grazing management (i.e., paddock rotation interval) for the different equine stock classes (empty, pregnant, mares with foals). Stocking and grazing management influenced the pasture available and subsequently, the grazing behaviour as determined by the difference between pasture mass of lawns and roughs. The difference between pasture mass of lawns and roughs was reduced with increasing stocking density and decreasing pasture availability, and increased under conditions of high stocking density (>2 mares/ha) and low pasture availability (<400 kg DM/ha/horse). Modification of grazing behaviour could affect the nitrogen-leaching potential by modifying the size of manure-deposition area and the N-loading rate on urine and dung patches. The complex relationship between farm, horse and management factors needs to be included when estimating nitrogen leached from equine properties.

Milk production and rebreeding performance of mixed-aged dairy cows mated to Angus or Hereford bulls - Coleman LW; Back PJ; Blair HT; Lopez-villalobos N; Hickson RE (New Zealand Journal of Animal Science and Production, 2019)
Approximately 72% of New Zealand dairy cows are artificially mated to generate replacement heifers. There is an opportunity to mate the remaining dairy cows to beef bulls, generating a calf that has value as a beef-cross-dairy animal. Angus and Hereford are the predominant beef breeds in New Zealand, with Hereford the most common beef breed used in the dairy industry. The aim of this experiment was to determine whether there was a difference in milk production and rebreeding performance of mixed-aged dairy cows producing a calf sired by an Angus or Hereford bull, and if calf birth weight influenced these parameters. Cows were artificially bred to Angus or Hereford bulls. Service sire-breed had no effect on milk production in early lactation. Cows producing Angus-sired calves had a 2.4 kg greater 253-day protein yield (P<0.05) than did cows producing Hereford-sired calves, however, there was no effect of calf sire-breed on the 253-day yields of milk, fat and milksolids. The in-calf rate and inter-calving interval did not differ between service sire-breed. There was no effect of calf birth weight on milk production, in-calf rate or inter-calving interval. The results of this experiment suggest that there are no negative effects associated with artificially breeding cows to Angus compared to Hereford bulls.

Regression of traits-other-than-production phenotypes for cows milked once a day on estimated breeding values obtained from cows milked twice a day - Sneddon NW; Lopez-villalobos N; Garrick DJ; Rocha JF; Donaghy DJ (New Zealand Journal of Animal Science and Production, 2019)
The use of traits other than production (TOP) to aid selection for conformation fit-for-purpose offspring becomes more important as once-a-day (OAD) milking for whole or part season becomes more common. In 2013 Massey University Dairy 1 farm transitioned their mixed-breed herd milked twice a day (TAD) to an OAD spring-calving system. All cows on the farm were scored for 14 inspector TOP traits and four farmer-scored traits for a total of 1,163 records over five seasons (168 to 254 cows per year). The scores were adjusted for age of the cow and season. The adjusted phenotypes for all cows for each trait were then regressed on their corresponding nationally-produced TAD estimated breeding values (EBV), which had been calculated without using these phenotypes. The four farmer-scored traits had the lowest relationships with EBV. Estimates of regression coefficients near one were observed for the udder traits (udder support, rear udder, front teats, udder overall), dairy conformation and body capacity. This supports the use of national EBVs in OAD herds derived mostly from records on daughters in TAD herds.

Relationships between deer temperament and production traits - Ward JF; Schütz KE; Wheeler M; Asher GW (New Zealand Journal of Animal Science and Production, 2019)
It is well-recognised by producers that the temperament of farmed deer (Cervus elaphus spp.) influences how they respond to management practices, such as transport and yarding, but less is known about how temperament influences productivity. This study aimed to investigate relationships among temperament and production parameters by analysing a data set (n=1647) of rising one-year-old deer. Four production categories (growth, immune function, eye muscle and reproduction) and five measures of temperament were recorded from weaning until either pre-slaughter or after first mating (3 to 12 or 18 months of age) at different ages depending on the trait. Temperament traits had low heritability estimates (h2=0.01 to 0.17, P>0.05), indicating genetic selection for these traits would be slow. The temperament traits of animals were generally consistent from weaning (at 3 months) until slaughter (at 10-12 months). Animals that were calm and easy to handle grew faster and may have better immune function compared to animals that were more agitated in the presence of humans. More research is needed to investigate the relationships between temperament, immune function, reproduction and productivity in farmed deer.

Strategic feeding management to mitigate enteric methane emissions and urinary nitrogen excretion - Garrett K; Beck MR; Gregorini P (New Zealand Journal of Animal Science and Production, 2019)
MINDY, a mechanistic and dynamic dairy cow model was used to explore strategic feeding managements in early (EL) and late lactation (LL), with the aim of reducing enteric methane (CH4 g d-1) emissions and urinary N (UN g d-1) excretion, while maintaining milk production. Strategies explored were a factorial arrangement of (1) herbage allowances (20, 30, 40, or 50 kg d-1), (2) times of herbage allocation (AM or PM), (3) supplement types (barley grain, maize grain and silage) and (4) times of supplement allocation (AM, PM, or both). A Pareto front analysis was conducted to identify ‘best compromise’ treatments. Increasing herbage allowance increased consumption of fermentable carbohydrates and N, resulting in greater CH4 and UN emissions per cow. Allocating herbage in the PM rather than the AM increased dry matter intake by 1.9 and 1.7% and milk solids (MS) by 2.3 and 0.7% in EL and LL, respectively. Afternoon forage allocation produced more CH4 (5.1 and 3.6%) and less UN (4.7 and 7.8%) in EL and LL, respectively. Morning supplement allocation on average yielded the lowest CH4 and UN emissions. Results indicate that feeding management can mitigate both UN and CH4 however, MS production can be compromised depending on stage of lactation.

Using leafy turnip to maintain growth rates of dairy heifers during summer - YC Fan; Purchas GS; Hickson RE; Back PJ (New Zealand Journal of Animal Science and Production, 2019)
In New Zealand, growth rates of dairy heifers can be restricted during late summer/early autumn due to inadequate pasture production and quality, which may delay puberty and compromise lactational performance, and, ultimately reduce their longevity in the herd and overall farm profits. The aim of this experiment was to determine the effect of feeding leafy turnip as an alternative summer forage to ryegrass-based pasture on the growth rate of heifers. Forty-five heifer calves aged six months were assigned to one of two treatment groups: (1) ryegrass-based pasture and (2) leafy turnip and were fed a combination of these feeds during summer/early autumn. Calves fed a greater proportion of leafy turnip were heavier (235.6 ± 3.8kg, P<0.05) and had greater average daily gain (0.74 ± 0.01 kg/day, P<0.05) than calves fed a greater proportion of pasture (218 ± 3.9 kg and 0.59 ± 0.01 kg/day), primarily due to pasture supply being restricted during the latter part of the experiment. The greater liveweight advantage from feeding leafy turnip remained for two months. Leafy turnip could be considered as an option to maintain growth rates of dairy heifers when pasture supply is restricted.

Anthelmintic resistance: a perspective on our current understanding and ability to control this problem - Pomroy WE (New Zealand Journal of Animal Science and Production, 2018)
Regimens to prevent the development of anthelmintic resistance (AR) have been promoted for many years. All reflect some appreciation of the selection pressure that different anthelmintic treatment policies apply to nematodes but AR is clearly more complicated than this for reasons we still do not yet understand sufficiently well. Whilst managing a refugia population on a farm is important to limit the development of AR there are many aspects that are not understood. Why is AR more common in some species than others, especially for some such as Dictyocaulus where there is clearly a short-lived refugia population and heavy selection pressure yet no recorded AR. The cost of AR to farmers has slowly escalated over the years and using a New Zealand example it can be estimated for a typical sheep farm that the cost of using a single active of an older anthelmintic such as levamisole compared to a newer anthelmintic such as monepantel is about NZ$3.27 per lamb raised. Diagnosis of AR continues to largely rely on the use of faecal egg count reduction tests. These are a very crude tool but generally acceptable for sheep. However, for cattle and farmed deer it is difficult to get egg counts high enough to conduct a meaningful test. Clearly more effort is needed to understand the mechanisms associated with AR and to develop better diagnostic tests so that farmers with their advisors are better able to achieve sustainable helminth control.

Assessment of vigour in early life of dairy calves in New Zealand - Gillingham J; Coleman LW; Back PJ; Mueller K; Hickson RE (New Zealand Journal of Animal Science and Production, 2018)
Vigour of dairy calves in the first few days of life may be a relevant predictor of subsequent performance in an artificial-rearing system. This experiment aimed to evaluate two scoring systems to determine whether they detected variation in beef-sired calves born in the New Zealand pastoral dairy system. The scoring systems included a vigour score devised for housed dairy calves in Canada which had a range of physical and physiological parameters assessed, and a drinking score assessed at the feeder in the first few days of life (1=calf does not attempt to suck on feeder, 5=calf drinks vigorously for the whole feed). Calves generally scored highly (17-21 out of a possible 22 points) on the vigour score and meconium staining, head/tongue swelling, movement and heart rate showed little to no variation among calves. The drinking score showed that few calves scored in the low categories, and the scoring system may be improved by creating greater separation within the higher categories. Angus-cross calves were more likely to have a higher drinking score than Hereford-cross calves, and light or young calves were more likely to have low drinking scores.

BRIEF COMMUNICATION: Differential expression of lactoferrin and insulin-like growth factor-1 genes in milk from cows milked once and twice a day - Gedye K; Notcovich S; CorreaLuna M; Ariyarathne P; Heiser A; Lopez-villalobos N (New Zealand Journal of Animal Science and Production, 2018)
Dairy farming in New Zealand has traditionally utilized a twice a day (TAD) milking system, but milking once a day (OAD) for the entire lactation is also practiced by a significant proportion of dairy farmers. This study reports on the differential gene expression in milk from OAD and TAD cows. Three predominant dairy breed group of New Zealand, Holstein-Friesian (F), Jersey (J) and F×J crossbred (F×J) were included in samples collected from both milking regimens. RNA was extracted from milk from 45 OAD and 42 TAD dairy cows during early lactation, and used to determine lactoferrin (LF) and insulin-like growth factor-1 (IGF-1) gene expression using qPCR. Compared to TAD cows, cows milked OAD had higher expression of the LF gene (1.38 vs 1.30 folds, P=0.08) and the IGF-1 gene (1.65 vs 1.48 folds, P=0.09). These results suggest that milking frequency affects the expression of milk composition genes at early lactation.

BRIEF COMMUNICATION: Effect of maternal diet in late gestation on development of dairy calves - Moonsan Y; Thomas C; Bryant RH; Edwards GR (New Zealand Journal of Animal Science and Production, 2018)
To investigate whether feeding strategies to reduce urinary N excretion would have negative effects on calf development, two feeding systems were compared. A total of 190 pregnant, Friesian × Jersey dairy cows were randomly allocated to one of two groups and offered either a low crude protein diet of maize silage and fodder beet (LCP) or a moderate CP diet of lucerne silage and fodder beet (MCP) for eight weeks prior to calving. Apparent metabolisable energy (ME) intake of dams was similar (110 MJME/cow/day) but CP concentration was greater for MCP than LCP (13.4 vs 7.5% of the DM). There was no effect of maternal diet on calf birth weight (33.0±0.5 kgLW) or morphometric measurements; heart girth (72.8±0.5) spine length (54.4±0.4) or hip height (73.1±0.4 cm). These results suggest that dietary protein restriction in late gestation does not have any immediate negative effects on in utero calf development.

BRIEF COMMUNICATION: Effect of timing of maize silage supplementation on grazing behaviour of dairy cows during a short grazing session on a ryegrass-based herbage - Al-marashdeh O; Gregorini P; Edwards GR (New Zealand Journal of Animal Science and Production, 2018)
The objective of this experiment was to compare rumen degradation characteristics of ryegrass (Lolium perenne), white clover (Trifolium repens) or plantain (Plantago lanceolata) harvested either in the morning (0700) or afternoon (1600). Fresh herbage material from each treatment was weighed into duplicate nylon bags and incubated in four lactating Jersey × Friesian dairy cows with rumen fistula. Differences in nutritive value between forage types was greater than effect of harvest time as was the effect on rumen degradation characteristics. Plantain had faster (P<0.001) DM disappearance rates than perennial ryegrass-white clover (12.2 vs 8.80 %/hr). The soluble fraction was greater (P=0.001) for forages harvested in the afternoon (25.2% of DM) than those in the morning (15.4% of DM) regardless of forage type. Nitrogen degradation was almost complete (>95% of N) and similar for all treatments (P>0.05). An interaction for effective degradability revealed there was no effect of harvest time on DM and OM for plantain. However, perennial ryegrass-white clover harvested in the afternoon has a greater effective degradability of DM and OM than that harvested in the morning. This suggested there is a larger influence of harvest time on some degradation characteristics of perennial ryegrass-white clover compared with plantain.

BRIEF COMMUNICATION: Impact of maternal plane of nutrition, ewe weight and twinning on fetal mammary gland development in sheep - McCoard SA; Adiletta AM; Jenkinson CMC; Peterson SW; Kenyon PR; Blair HT (New Zealand Journal of Animal Science and Production, 2018)
This study evaluated the effects of maternal nutrition, weight and gestation rank on fetal mammary gland development. Light (L) and heavy (H) single- and twin-bearing ewes were fed ad libitum (A) or maintenance (M) nutritional regimens from day 21 to day 140 of gestation and euthanised for tissue collection. Plane of maternal nutrition or maternal weight did not affect histomorphometry of fetal mammary glands. Singleton fetuses had 43% greater total duct area (P<0.05), 62% greater secretory cell area and 32% fewer ducts (P<0.05) but similar total lumen area, cell size and total cell number than twins. These results indicate that twinning reduces area of mammary ducts and secretory cell area while maternal weight and plane of nutrition from day 21 have little impact on mammary morphology at day 140 of gestation.

BRIEF COMMUNICATION: Milk production, feeding behaviour and rumen fermentation of dairy cows supplemented with winter brassica crops - Keim JP; Rodriguez JR; Balocchi O; Pulido R; Pacheco D; Muetzel S (New Zealand Journal of Animal Science and Production, 2018)
This study evaluated feeding behaviour, dry matter intake (DMI), rumen fermentation and milk production responses of lactating dairy cows supplemented with kale or swedes. Twelve multiparous early lactation dairy cows were randomly allocated to three dietary treatments in a replicated 3 x 3 Latin square. The control diet comprised 10 kg dry matter (DM) of grass silage, 4 kg DM of grass pasture and 8.8 kg DM of concentrate; 25% of the diet was replaced with kale or swedes. Cows supplemented with kale showed a lower DMI compared to cows supplemented with swedes and the control diet; whereas swedes supplementation increased eating time. Milk production responses were not affected by winter brassica supplementation. This resulted in a greater feed conversion efficiency of cows supplemented with kale compared to that of the control diet.

BRIEF COMMUNICATION: Milk production responses and rumen fermentation of dairy cows supplemented with summer brassica crops - Keim JP; Castillo M; Balocchi O; Pulido R; Pacheco D; Muetzel S (New Zealand Journal of Animal Science and Production, 2018)
This study evaluated the dry matter intake (DMI), rumen fermentation and milk production responses of lactating dairy cows supplemented summer brassicas. Twelve multiparous lactating dairy cows were randomly allocated to three dietary treatments in a replicated 3 x 3 Latin square design. The control diet was composed of 16.2 kg DM of grass silage and 4.5 kg DM of concentrate; 25% of the diet was replaced by rape or turnip. Cows supplemented with summer brassicas showed a lower DMI (P<0.001) compared to the control diet, however milk yield was not affected, resulting in a greater feed conversion efficiency (1.35 for turnip and rape v/s 1.27 for the control diet). Rape supplementation significantly increased microbial protein (P=0.002). VFA concentration and the relative proportion of propionate were increased with turnips, whereas rape increased the acetate:propionate ratio. Mid-lactating dairy cows fed with brassicas are able to maintain production despite the reduced intake, probably due to improved rumen fermentation and therefore nutrient utilisation.

BRIEF COMMUNICATION: Potential alterations in New Zealand sheep, beef cattle and deer numbers due to climate change: what can genetics offer? - Mcrae KM; Rowe S; McEwan JC (New Zealand Journal of Animal Science and Production, 2018)
Many producers of red meat in New Zealand run enterprises consisting of a mix of sheep, beef cattle and deer, with obvious differences in species ratios across regions when aggregated. The aim of this study was to use these regional species ratios to predict livestock number changes in New Zealand in response to climate change. Simple linear regression was performed using mean temperature and species ratio (sheep, beef cattle and deer) for each region. The slopes of these linear equations were used to estimate “business-as-usual” for each region in year 2100 under different models of climate change. An overall decrease in sheep and deer numbers by up to 38% and 75%, respectively, is predicted, along with an increase in beef cattle numbers by up to 60%. Genetics provides an opportunity to select for animals that are adapted to the changing environment through reproductive plasticity, disease resistance, and heat tolerance, and therefore to moderate these predicted changes.

BRIEF COMMUNICATION: Re-designing New Zealand’s productivist livestock production systems: Current strategies and next steps - McWilliam W; Gregorini P (New Zealand Journal of Animal Science and Production, 2018)
Intensive, monotonous and specialized pastoral livestock production systems (productivist systems) are under significant pressure to reduce environmental impacts, increase biodiversity, animal welfare, and resilience. Efficiency/substitution strategies have been advanced to improve them, focusing on adjusting system components to reduce externalities of regulatory concern. They have received much research attention, policy and farmer support. However, many argue environmental impacts are not sufficiently reduced, and biodiversity, animal welfare and resilience remain unchanged. Biodiversity farming strategies have also been promoted, based largely on their application to less productive land. They are more spatially and/or temporally complex, less specialized, and promise to reduce multiple environmental impacts, improve support for biodiversity, animal welfare and increase resilience. However, few systems have been designed for highly productive land, there is insufficient amount of supporting research, and less policy support and awareness among farmers. Therefore, there is a high degree of uncertainty about their supporting farming practices, ecosystem services, and viability. Through multi-disciplinary research teams, and holistic and expanded spatial and temporal perspectives, Universities can play a key role in exploring, ex ante evaluating, and demonstrating new innovative system alternatives, that reduce this uncertainty and facilitate the transition to healthier viable animal production systems.

BRIEF COMMUNICATION: Reproductive performance of herds milked once a day all season compared with herds milked twice a day all season - Hemming NV; McNaughton LR; Couldrey C (New Zealand Journal of Animal Science and Production, 2018)
The objective of this study was to compare the reproductive performance of herds milked once a day (OAD) for the whole season with that of herds milked twice a day (TAD) for the whole season. Herds were classified as OAD or TAD if they herd tested ≥ three times a season and >90% of animals had the same milking regime (OAD or TAD) at each test. Once the OAD herds were identified, the closest geographical TAD herd was identified and included in the dataset for the 2014 to 2016 seasons. Only herds with a Detailed InCalf Fertility Focus report were analysed (OAD n=75, TAD n=76). The means of five key reproduction measures were analysed and the means were significantly different for all measures (P<0.001). The OAD herds had a 7.7% higher mean herd 3-week submission rate (OAD=84.6%, TAD=76.9%), 7.9% higher mean conception rate (OAD=60.1%, TAD=52.2%), 10.4% higher mean 6-week in-calf rate (OAD=74.8%, TAD=64.4%), 4.8% lower mean not-in-calf rate (OAD=12.8%, TAD=17.6%), and 4.3% more of the herd calved by week six of calving (OAD=88.2%, TAD=83.9%) than TAD herds. These results indicate that herds milking OAD for the whole season have, on average, better reproductive performance than those milked TAD the whole season.

Calf-rearing systems on dairy farms and specialist calf rearing units: results of a New Zealand survey - Thompson BC; Muir PD; Ward KR (New Zealand Journal of Animal Science and Production, 2018)
Calf-rearing practices were surveyed on 297 dairy farms with an average of 82 heifer and 24 bull calves reared. Only 21% of the properties fed colostrum immediately on arrival at the dairy shed, and 30% did not feed their calves for at least 8 hours after pickup. Rearing systems were highly variable although most fed twice a day on high milk volumes. Many (40%) did not know how much milk they fed to their calves and for those who did, the average was 316 litres per calf. Calves were weaned off milk at an average of 9.7 weeks. Calf-rearing practices were surveyed on 100 bull-calf-rearing properties rearing on average 259 calves annually. Larger rearers (>600 calves) tended to feed whole milk whereas smaller rearers tended to feed calf-milk replacers. Most rearers fed milk once a day and fed an average of 155 litres/calf over rearing. Calves were weaned at an average of 6.5 weeks. Bullcalf rearers feed to a weight target and a budget which resulted in a greater focus on performance and feed costs. Dairy farmers could significantly reduce both costs and time inputs by monitoring performance, feeding milk once a day and weaning earlier.

Characteristics of the grazing and farm management of broodmares on commercial Thoroughbred stud farms during spring - Bengtsson J; Rogers CW; Back PJ; Emanuelson U; Roca J; Gee EK; Bolwell CF (New Zealand Journal of Animal Science and Production, 2018)
Thoroughbred broodmares in New Zealand are at greater odds of exposure to Leptospira than racehorses, possibly as a result of aspects of the on-farm pasture-based management. To identify biologically plausible risk factors cohorts of broodmares were prospectively followed on four Thoroughbred stud farms for a five-week period during the 2017-2018 season. Up to three cohorts of mares within each group of mares identified at the start of the study as empty (not in foal), in-foal, or mares having just foaled (with foal at foot) were followed on each farm and measurements made of pasture dry matter (DM) on offer, paddock location, mare cohort structure and farm management. The farm with stallions had a greater number of changes in mare cohort membership (2 (1-2) vs. 0 (0-1), P=0.001). The total pasture DM on offer was least for empty mares compared to in-foal mares, and mares with foals at foot (1483 (1157-2380) vs. 2070 (1499-2534) vs. 2299 (1390-3196) kg DM/ha, P=0.009). Pregnant mares had the greatest stocking density 4 (2 -6) mares/ha, due to use of small foaling paddocks. The low pasture DM on offer and high stocking rate for empty mares may provide a mechanism for exposure to environmental sources of Leptospira.

Differences in birth weight and neonatal survival rate of lambs born to ewe hoggets or mature ewes - Pettigrew EJ; Hickson RE; Blair HT; Griffiths KJ; Ridler AL; Morris ST; Kenyon PR (New Zealand Journal of Animal Science and Production, 2018)
This experiment investigated differences in birth weights and survival in lambs born to hogget and mature ewes. It included 1082 mature ewes with a scanning rate of 1.87 fetuses per ewe joined and 1026 hoggets with a scanning rate of 0.80 fetuses per hogget joined, that were bred together, and lambed separately, under commercial farming conditions. At lambing, birth weight, lamb vigour score, and ewe maternal behaviour score were recorded. Lambs born to hoggets were lighter and less vigorous than lambs born to mature ewes (P<0.05). Single-born lambs were heavier at birth (P<0.05), and had greater survival at birth (P<0.05) than did twin-born lambs. Twin-born lambs were heavier (P<0.05) at birth, and had greater survival at birth (P<0.05) than triplets. There was an interaction of dam age and birth rank on lamb survival to weaning (P<0.01). At all birth ranks lambs born to hoggets had lower survival to weaning than lambs born to mature ewes, and the difference in survival increased with increasing birth rank. Lambs that had a vigour score of 1 had lower survival (83.5%; P<0.05) than lambs that had a vigour score of either 2 or 3 (88.6- and 91.4%, respectively). Maternal behaviour score did not affect lamb survival (P>0.05). Lambs born to hoggets are at greater risk of mortality, so farmers need to prioritise their time and resources towards hoggets at lambing time.

Economic value of productive life of cows on organic dairy farms in the United States - Lopez-villalobos N; Schinckel AP; Schultz MM (New Zealand Journal of Animal Science and Production, 2018)
Organic milk production is an important sector of the US dairy industry. Productive life, defined as the time that a cow remains in the herd after first calving, is a trait of economic importance in organic dairy farming affecting the age structure of the herd and replacement costs. Productive life is of economic importance for inclusion in breeding objectives for organic milk production, which determine its value for selection. The objective of this study was to estimate the economic value (EV) of productive life for cows on certified organic dairy farms in the US using a farm-simulation model. Annual net farm income (NFI) per cow was calculated as gross income minus production costs. Income was derived from the sale of milk, disposed animals and other income. Milk income was calculated as US$ 0.809/kg milk. Cost of organic feed was US$ 0.308/kg DM. The average productive life of the herd was 1,302 d with an annual replacement rate of 22.1%. The herd NFI was US$ 520.70/cow and the EV for productive life was US$ 1.24/d. This value is higher than the EV of productive life included in the Net Merit (US$ 0.69/d) or Grazing Merit (US$ 0.43/d) indexes used for conventional US dairy cattle.

Effects of a daily dose of zeolite on rumen ammonia of lactating dairy cows consuming fresh-cut ryegrass pasture - Beukes PC; Gregorini P; Waghorn GC; Selbie PB (New Zealand Journal of Animal Science and Production, 2018)
Zeolites are aluminosilicates that can be safely fed to ruminants on a daily basis. They have a strong affinity for cations, including ammonium (NH4 +), which creates the potential to adsorb excess ammonium released in the rumen and reduce urinary nitrogen (N) excreted. The main objective of this proof-of-concept study was to evaluate the effect of a single dose of 300 g of zeolite, deposited into the rumens of cannulated dairy cows before the main morning meal of fresh-cut ryegrass pasture, on changes in rumen ammonium concentrations over the following 8 h. The two-week trial was a cross-over design with 12 cows, either fed ryegrass as a sole diet (Control) or with zeolite (Zeolite). There was a consistent trend for rumen ammonium concentrations in the zeolitetreated cows to increase more slowly over time, and were lower than control cows 8 h after the zeolite was given (P = 0.08). This study provides some indications that a daily dose of zeolite, fed at the onset of the morning meal, may have a moderating effect on rumen ammonium concentration, and reduce plasma urea N concentrations in lactating dairy cows fed a ryegrass-dominant diet.

Effects of early weaning onto herb-clover mixes on lamb carcass characteristics - Wong HX; Schreurs NM; Corner-Thomas RA; Ekanayake WEMLJ; Cranston LM; Morris ST; Kenyon PR (New Zealand Journal of Animal Science and Production, 2018)
Ewes and their twin lambs (weighing at least 16 kg) were allocated to three treatments: lambs with dams on ryegrass-white clover (RG-WC) pasture until 15 weeks of age (GRASS) (lambs; n=50), lambs with dams on herb-clover mixes (plantain, chicory, red and white clovers) until 15 weeks of age (HERB) (lambs; n=50), and lambs weaned early (8 weeks old) onto herb-clover mixes and dams on RG-WC pasture (EARLY) (lambs; n=50). Average daily gain, GR soft-tissue depth and muscularity of lambs in EARLY and GRASS were lower than those in the HERB treatment (P<0.05). The muscle to bone ratio of lambs in HERB treatment was higher than those in the EARLY treatment (P<0.05). Lambs can be weaned at 8 weeks of age onto herb-clover mixes to achieve similar carcass characteristics compared to lambs weaned at 15 weeks of age on RG-WC pasture. Lambs weaned early onto herbclover mixes had lower growth rates than the lambs not weaned early on herb-clover mixes. There were no negative effects on lamb carcass characteristics and lean-meat yield (LMY) when lambs were slaughtered at a set weight.

Effects of lamb live weight, sex and forage type (grass or plantain-clover mix) on lamb growth during summer - Cranston LM; Schreurs NM; Corner-Thomas RA; Kenyon PR; Morris ST (New Zealand Journal of Animal Science and Production, 2018)
Two studies were carried out, over consecutive summers, to examine the effect of lamb sex and initial live weight on liveweight gain when grazing a grass-based sward (undeveloped hill country pasture) or a plantain-clover mix (plantain, red clover and white clover sown on cultivatable hill country). There were no interactions (P>0.05) between the sex of the lamb, initial live weight or forage type on lamb liveweight gain. In year 1, ewe lambs grew at a slower rate than wethers (169 vs 181 g/day; P<0.01), but there was no difference between the two sexes in year 2 (P>0.05). In both years lambs with a lighter initial liveweight profile were also lighter (P<0.001) at the end of the study, but there was no difference (P>0.05) in the liveweight gains of the light and heavy lambs. In both years lambs grazing the plantain-clover mix grew 47-141 g/day faster than did lambs grazing the grass-based sward (P<0.001). This indicates that the plantain-clover mix can be utilised for a range of lamb classes, with similar positive results.

Effects of vehicle type, driver experience and transport management during loading and in-transit on the welfare of road transported horses in New Zealand - Riley CB; Rogers CW; Padalino B (New Zealand Journal of Animal Science and Production, 2018)
The transport of horses for pleasure and commerce occurs frequently in New Zealand. In contrast to commercial livestock transport, most are transported by nonprofessional drivers in vehicles accommodating 2-3 animals; these do not have design standards that specifically address livestock welfare. The study identified if vehicle type and other factors were associated with transport related behavioural problems (TRBPs) during loading and in-transit. An online survey addressing transport practices and TRBPs was distributed throughout the New Zealand horse industry. Univariate and multivariate analyses identified risk factors for TRBPs (P<0.2) during loading and in-transit. Use of a whip or food during loading, feeding en route, travel frequency, and transport vehicle type were risk factors for TRBPs during loading (P<0.02). The ability to assess horse distress, feeding en route, the use of a whip for loading and vehicle type were risk factors for TRBPs in-transit (P<0.03). Commercial transport and transport in large trucks were associated with TRBPs during loading and in-transit respectively. Findings support other published evidence that adverse welfare outcomes for horses may be associated with vehicle types and other factors. Further study is required to differentiate the role of vehicle design or type from horse loading and transport practices in New Zealand.

Faecal avoidance in Romney sheep lines selected for resistance or resilience to gastro-intestinal nematodes - Hamie JC; Logan CM; McAnulty RW; Greer AW (New Zealand Journal of Animal Science and Production, 2018)
Faecal avoidance was assessed in Romney lambs from lines selected for resistance or resilience to gastro-intestinal nematode parasites. Ten lambs from each selection line that were maintained in separate farmlets and naturally exposed to parasites were assessed on distance grazed from either a mud-clay or faecal ball at 130, 150, 180 and 210 days-of-age. Resistant line animals maintained lower faecal-egg counts compared with resilient lambs, viz. 25.6 c.f. 771.0 eggs per gram of faeces (P<0.001) and greater Trichostrongylus colubriformis-specific immunoglobulin G absorbance (P=0.005) indicating differences between selection lines in parasite loading and immunlogical status. Grazing distance from the object was greatest for faecal ball, viz. 11.53 ± 1.14 cm compared with mud-clay ball, viz. 4.19 ± 1.00 cm (P<0.001) and decreased with time (P<0.001). Grazing distance tended to be greater for resilient, viz. 8.63 ± 1.14 cm than resistant, viz. 7.09 ± 0.99 cm (P=0.09) but there was no interaction between selection line and ball type (P=0.709) indicating similar levels of faecal-specific aversion between the selection lines. These results suggest that the lesser infection levels in resistant-line animals when grazing is unlikely to be due to reduced exposure to infective larvae as a consequence of greater faecal avoidance.

Genetic and phenotypic correlations between production traits and adult body condition scores in New Zealand merino ewes - Tait IM; PR Kenyon; Garrick DJ; Pleasants AB; Hickson RE (New Zealand Journal of Animal Science and Production, 2018)
Genetic and phenotypic correlations between adult body condition scores (BCS) throughout the production cycle and eye muscle depth, fat depth, two-year-old greasy fleece weight, fibre diameter, staple length and staple strength were estimated from 2,007 pedigree-recorded merino ewes born between 2013 and 2015. The heritability estimates of BCS at pre-mating, mid-pregnancy, pre-lambing and weaning were 0.66, 0.39, 0.46 and 0.32 respectively. The heritability estimates for yearling greasy fleece weight, fibre diameter and staple length were 0.65, 0.86 and 0.73 respectively, and all these traits were positively genetically correlated with BCS. The genetic correlations among the four BCS measurements ranged from 0.39-0.83, while the phenotypic correlations ranged from 0.22-0.45. Genetic correlations between BCS and fat depth ranged from 0.67 to 0.83. Given the high heritability of BCS and high genetic correlations between BCS measurements, there is clear scope for selection to alter BCS. Mating appears to be the best time to record BCS for genetic selection, as it had the greatest heritability estimate and the greatest genetic correlations with ultrasound measurements of fat depth and eye-muscle depth and all wool traits except fibre diameter coefficient of variation and greasy fleece weight.

Genetic parameters for milk urea concentration and milk traits in New Zealand grazing dairy cattle - Lopez-villalobos N; CorreaLuna M; Burke JL; Sneddon NW; Schultz MM; Donaghy DJ; Kemp PD (New Zealand Journal of Animal Science and Production, 2018)
The aim of this study was to estimate genetic parameters for milk urea (MU), yields of milk (MY), fat (FY), crude protein (CPY) and lactose (LY), concentrations of fat (FP), crude protein (CPP) and lactose (LP) and efficiency of crude protein utilisation (ECPU) in grazing dairy cows. Data consisted of 1284 herd-test records of milk traits and MU from 468 mixed-breed cows in two herds. Univariate and bivariate repeatability animal models were used to estimate heritabilities (h2) and genetic (rG) and phenotypic (rP) correlations among the traits. Estimates of h2 for MU and ECPU were 0.24 and 0.11, whereas h2 estimates for MY, FY, CPY and LY ranged from 0.10 to 0.20. Estimates of h2 for FP, CPP and LP were 0.37, 0.59 and 0.19, respectively. The estimates of rP for MU with other traits were near zero. The rG of MU with MY (0.38), and of MU with LY (0.31) were positive and significant (P<0.01) whereas the rG of MU with FP (-0.80), CPP (-0.66) and LP (-0.76) were negative and significant (P<0.01). The rG between MU and ECPU was -0.09. These estimates of genetic parameters can be used to predict genetic responses to selection for reduction of MU.

Genetic parameters of GreenshellTM mussel traits under two harvest seasons - Hess AS; Dodds KG; Roberts RD; King N; Symonds J; Clarke SM (New Zealand Journal of Animal Science and Production, 2018)
Greenshell™ mussels (GSM) are a mollusc endemic to New Zealand and are of economic importance to the New Zealand aquaculture industry. The primary focus of the GSM industry is selection for increased meat weight, however, aesthetics also influence marketability. This study focused on pedigree-based estimation of heritabilities and genetic correlations among GSM traits collected during two harvest seasons: standard and winter. Sizes and weights were highly heritable (0.41±0.07 to 0.92±0.09), and highly genetically correlated across traits and seasons (≥0.75±0.07). Meat cover and gonad scores (measures of visual appeal) had lower heritabilities than did size and yield traits (0.08±0.03-0.25±0.05). Under standard conditions, meat cover had a high genetic correlation with gonad condition scores (0.85±0.04). Under winter conditions the relationship between meat cover and gonad scores was negative (-0.52±0.19). Substantial GxE was observed across seasons (meat cover: rg=-0.58±0.16; gonad: rg=0.62±0.11). Progress made from genetic selection to increase meat yield while controlling for the size may be slow, so selecting for traits related to visual appeal may be preferable. Given that production traits are genetically similar across harvest conditions, selection within standard conditions is likely to improve performance in both standard and winter harvests, thereby allowing for an extended harvest period. However, the genetic improvement of visual appeal of the mussels is likely to be influenced by target harvest season.

Growth performance of crossbred dairy calves fed different milk allowances using an automatic feeding system - Groenendijk ME; Lowe K; Schreurs NM; Molenaar AJ; McCoard SA; Luo D; Khan MA (New Zealand Journal of Animal Science and Production, 2018)
The impact of feeding different levels of milk replacer via automated feeders on intake and growth was assessed in calves. Heifer calves (Holstein × Jersey; n=198; 11±4 days old) were randomly allocated to low-allowance (LA; n=67; calves were fed milk replacer at 10% of initial live weight), high-allowance (HA; n=65; calves were fed milk replacer at 20% of initial live weight), and ad-libitum (ADLIB; n=66; calves were given ad libitum access to milk replacer). Pelleted calf starter was provided ad libitum and daily individual intake of milk replacer and calf starter was measured via automated feeders. Calves were gradually weaned from 69±2 days over 14 days. Average daily weight gain during pre-weaning was the highest (P<0.05) for ADLIB (0.69±0.02 kg/ day), followed by HA (0.61±0.02 kg/day) and LA (0.54±0.02 kg/day) calves. Calf starter intake was the lowest (P<0.05) in ADLIB calves followed by HA and LA calves. The ADLIB calves had the lowest (P<0.05) calf starter intake during the week after milk weaning but it did not affect the live weight of calves. In conclusion, provision of more milk promoted pre-weaning growth, and restricted milk feeding to trigger solid feed intake failed to match that growth advantage.

Heritability of longevity in New Zealand dairy goats - Scholtens MR; Lopez-villalobos N; Garrick DJ; Blair HT (New Zealand Journal of Animal Science and Production, 2018)
Longevity is a trait of economic importance in dairy goat farming. Actual longevity (AL) is defined as the number of days from birth to when the animal leaves the herd, whereas functional longevity (FL) is defined as AL adjusted for first lactation energycorrected milk yield (ECMY). This study reports the heritability (h2) for AL and FL in New Zealand dairy goats. Records of longevity from 12,108 does born between 1993 and 2011 were analysed with a model that included the fixed effects of herdyear (does born in the same herd and year) and covariates for the proportion of Alpine, Nubian, Toggenburg and heterosis, and the random effect of animal. The model for FL was the same as AL, but included ECMY as a covariate. Average AL was 1,891 (SD=832) days. Estimates of h2 were 0.07 for AL and FL. The estimated regression coefficient for ECMY on AL was 0.56 days/ litre. There were significant differences in longevity among herds, indicating that management and feeding are important factors affecting longevity. Further research is required to estimate genetic correlations with economically important traits.

The impact of different management systems on behaviour and milk production of dairy ewes in different stages of lactation; a case study - Bliss AE; Chylinski C; Luo D; Schütz KE; Lowe K; Peterson SW; Stevens D; MacDonald T; McCoard SA (New Zealand Journal of Animal Science and Production, 2018)
Comparisons of New Zealand dairy sheep farm systems are currently lacking. The aim of this preliminary study was to evaluate the effects of different management systems on the behaviour and milk production of East Friesian cross-bred sheep at different stages of lactation. Two study groups were evaluated. In study group 1, a mob of 479 mixed-age, mid-lactation ewes were housed 24 h/day, and a separate mob of 473 mixed-age, mid-lactation ewes were managed in a hybrid system (housed between morning and afternoon milkings; grazed lucerne overnight). Both received a total mixed ration (TMR) indoors. In study group 2, a mob of 604 mixed-age, late-lactation ewes grazed pasture 24 h/day, and a separate mob of 452 mixed-age late-lactation ewes were in a hybrid system, grazing pasture overnight. For both study groups, individual milk yield, walking distance, lying time, live weight (LW), and body condition score (BCS) were recorded. All sheep gained BCS and LW except fully grazed late-lactation ewes. For study group 1, fully housed ewes in mid-lactation lay down less during the day, but more overnight compared to those in the hybrid system, likely due to the latter grazing overnight. Lying bout times were similar between groups, while milk yield was 29% less in housed ewes compared to the hybrid ewes. For study group 2, grazing ewes in late-lactation lay down more, had longer lying bouts, and walked further daily than those in the hybrid system, but both late-lactation treatment groups had similar milk yields. In summary, the hybrid management system seems to improve milk yield in mid-lactation compared to the fully housed system, whereas there was no difference between the hybrid and fully grazed systems in late-lactation. Lying behaviour and walking distances (group 2 only) differed among different systems, however, it is unclear what this means in terms of animal welfare, and warrants further investigation.

In sacco digestion kinetics of plantain and ryegrass-white clover harvested in the morning and afternoon - Box LA; Edwards GR; Bryant RH (New Zealand Journal of Animal Science and Production, 2018)

The influence of dam live weight on the carcass weight of rising-yearling farmed red deer and wapiti crossbreds - Ward JF; Meenken ED (New Zealand Journal of Animal Science and Production, 2018)
The New Zealand Deer Industry set productivity improvement targets in 2012 for the following 10 years, many related to breeding hinds. Increasing progeny carcass weight was the key trait of interest outside of hind reproductive performance. In this study, the productive output of dams was investigated. Data were collected from red deer and wapiti crossbred progeny (n=2289) born and raised on three farms over five years (2011-2015) from red deer dams (n=1353), mated to 51 red or wapiti stags. Data were analysed using a restricted-maximum likelihood (REML) mixed-model approach to produce predictive models of dam production outputs across a range of dam live weight. The most influential fixed effect in the model was sex, followed by dam mature weight. Predictions were made for progeny carcass weight of male red deer, and of male and female wapiti crossbreds at a mean slaughter age of 348 days from dam mature live weight. For the PIP target 115 kg red deer dam, the goal of a 64 kg progeny carcass was not achieved in this population, with a 115kg red deer dam predicted to produce 58.0, 63.0 and 54.5 (SEM 0.7, 0.9 and 0.9) kg carcasses for red male, wapiti crossbred male and females respectively. Industry should increase selection for hind productive efficiency.

Investigation into udder characteristics, mastitis and milk production in crossbred sheep - Yusuf OM; Logan CM; Ridler AL; Greer AW (New Zealand Journal of Animal Science and Production, 2018)
Associations between udder characteristics, milk yield, milk somatic cell counts (SCC) and prevalence of mastitis were evaluated in 121 twin-suckled crossbred non-dairy ewes at four, eight and twelve weeks after parturition. Overall, milk production decreased with time, being 1.09 ± 0.04 litres per four hours at week four of lactation, 0.68 ± 0.02 litres at week eight and 0.48 ± 0.01 litres at week twelve with corresponding mean SCC of 0.32 x 106 cells mL-1, 0.39 x 106 cells mL-1 and 0.28 x 106 cells mL-1, respectively. Incidence of mastitis was 12.7%, 9.8% and 8.9% for weeks 4, 8 and 12, respectively. Of the 20 individuals that displayed SCC indicative of mastitis, only 5 had elevated SCC at more than one sampling time. No consistent association was observed between SCC and visual scores for udder depth, udder distention, degree of separation or teat placement (P>0.05 for all). Milk volume and weight of lamb was greater for ewes with an udder depth of 3 compared with 4 with no other associations evident (P>0.05). Overall, the incidence of subclinical mastitis was low but present in this flock with the udder characteristics assessed here providing poor indicators of either mastitis or milk production.

Invited opinion paper: Ways food systems undermine choice to the detriment of herbivores and humans - Provenza FD; Gregorini P (New Zealand Journal of Animal Science and Production, 2018)
Landscapes with rich arrays of forages and foodscapes with rich assortments of wholesome foods are nutrition centres and pharmacies for herbivores and humans. Whether herbivore or human, health ensues when cultures learn to combine biochemically rich foods into meals that nourish and satiate. Biochemically rich diets include not only energy, protein, minerals, and vitamins, but also a host of other compounds—such as phenolics, terpenes, and alkaloids—with nutritional, prophylactic, and therapeutic benefits. We discuss some not-so-obvious ways food systems undermine biochemically rich alternatives and choices to the detriment of herbivores and humans. We also consider how food systems can enable individuality in form (morphology), function (physiology), and behavior by providing biochemically rich foods. We conclude by discussing how providing a variety of wholesome foods— and letting the wisdom of the body guide food selection—can enhance the health and well-being of herbivores and humans.

Is it possible to produce good quality meat from Holstein-Friesian bulls? - Martin NP; Schreurs NM; Morris ST; McDade JL; Craigie CR; Hickson RE (New Zealand Journal of Animal Science and Production, 2018)
There is potential to increase the value of meat from Holstein-Friesian bulls by increasing the proportion of carcasses that are of suitable quality to be eligible for primal cuts sold in high-value markets. The objective of this study was to explore relationships between carcass and meat-quality traits from Holstein-Friesian bulls between 21-38 months of age, slaughtered on different occasions. Meat samples of M. longissimus lumborum were collected at slaughter and chill-aged at -1.5ºC for seven days. The means (±s.d.) were: carcass weight 313±29 kg (n=256), dressing-out 54.7±2.6% (n=256), ultimate pH 5.9±0.38 (n=221), shear force 11.34±4.93 kgF (n=221), cook loss 28.4±5.4% (n=220) and colour indexes (n=159) L* (lightness) 36.06±2.96, a* (redness) 12.38±4.04 and b* (yellowness) 8.74±2.24. A total of 80 samples (36%) were found to be both of acceptable tenderness (below 10.9 kgF) and pH less than 5.8. Alleviating meat pH issues is required to ensure high-quality meat from bulls that is suitable for high-value primal cuts.

Lamb castration and tailing practices in New Zealand: results of a questionnaire - Corner-Thomas RA; Ferguson MB; Kenyon PR; Stafford KJ; Pomroy WE (New Zealand Journal of Animal Science and Production, 2018)
There is a large body of literature that has examined the impacts of castration and tailing on lamb behaviour, stress response, pain and productivity (Fisher et al. 2010; Kent et al. 1993; Mellor et al. 2002; Mellor & Stafford 2000). Recently, Kerslake et al. (2015) investigated lamb tail docking, residual tail length and the reasons behind farmers’ choice to dock. There is little information available, however, regarding castration methods and reasons for the choice of leaving lambs entire, castrated or short-scrotumed. A printed questionnaire was distributed to ~12,000 farmers on the Beef + Lamb New Zealand database. The questionnaire contained 30 questions on aspects of management of flystrike, louse control, tailing and castration. Information was sought regarding percentage of lambs tail docked, method used to remove tails, reason for the tailing decision, proportions of male lambs left entire or castrated or short scrotumed, the method used to castrate or short-scrotum, and the reason for choice of male lamb type. A total of 1253 (10%) of questionnaires were returned. Of the farmers that responded, the most commonly used tailing method was a hot iron (61%), followed by rubber rings (31.4%). Lamb growth was the primary reason that farmers gave for leaving lambs entire, and to a lesser degree short-scrotum. The reason behind the decision to castrate was most commonly related to lamb behaviour, however, a number of reasons had similar frequencies (lambs stay cleaner, infertility and meat quality).

MATN3 underlies a QTL for stature in cattle - Lopdell TJ; Littlejohn MD (New Zealand Journal of Animal Science and Production, 2018)
Live weight (LWT) in dairy cattle is associated with milk production efficiency, and also has a high genetic correlation with stature. To identify genetic regions impacting stature and LWT, we conducted a genome-wide association study using 65,500 mixed-breed NZ dairy cattle and 16,243,015 imputed genotypes. We identified a quantitative trait locus (QTL) at BTA11:78- 79Mbp for stature that was significant at a genome-wide level (β=3.98mm ± 0.56; P=1.6×10-12) but not significant for LWT (β=1.253 ± 0.393 kg; P=1.4×10-3). Ensembl’s Variant Effect Predictor was used to search for coding variants to attempt to identify a candidate causative gene for this QTL, and gene expression from RNA sequence data representing 373 cows were analysed for 16 genes and 3,640 markers to highlight expression QTL (eQTL) in this region. The gene with the most significant eQTL was MATN3 (ENSBTAG00000020893; P=2.5×10-38), encoding a protein which is involved in bone development. The correlation between variant effects (-log p-values) was calculated for the stature QTL and MATN3 eQTL (r=0.584), with the same variant (rs475277351) most significant for both QTL. This suggests a common genetic signal underlying both QTL, supporting the hypothesis that the MATN3 gene underlies the stature QTL.

Metabolic profiles of non-lactating, pregnant heifers during transitioning from kale to swedes in Southland, New Zealand - Dalley DE; Sheahan A (New Zealand Journal of Animal Science and Production, 2018)
During winter 2014, a study was conducted in non-lactating pregnant dairy heifers to monitor changes in liver enzymes during a six-week period following a diet change from kale to swedes. Blood samples were collected from 20 cows on Days 0, 4, 7, 14, 28, and 42 after transitioning. Changes were recorded for most blood metabolites, in response to the change from kale to swedes, indicating potential liver inflammation or hepatic cell stress damage. On days four and seven, 6 and 8% of animals had lower than normal concentrations of AST, respectively. Elevated concentrations of GGT and GLDH, relative to Day 0, were recorded on Day 7 and 14 in individual cows. NEFA concentrations peaked on Day 4, possibly indicating a decrease in feed intake during the initial transitioning process. Up to 40 percent of the herd exhibited metabolic changes during the transition period. Although the concentration of some metabolites were above the normal range for individual animals between days 4 and 14, they had decreased to within the normal range by day 28, indicating that cows had become adapted to the new diet. Results suggest that, even with good practice, individual animals within a herd are at risk of liver stress when transitioning onto swedes.

Milk production and milk fatty acid composition of grazing dairy cows supplemented with fodder beet - Fleming AE; Edwards GR; Bryant RH; Dalley DE; Gregorini P (New Zealand Journal of Animal Science and Production, 2018)
A study was conducted to evaluate the effect of supplementing a perennial ryegrass-based diet with fodder beet on milk production and milk fatty acid (FA) composition, of dairy cows in early lactation. Sixty Friesian × Jersey cows, were blocked into six groups of 10 cows, and groups randomly allocated to three replicates fed either 18 kg DM/day of ryegrass herbage (H), or 14.4 kg DM/ day of ryegrass herbage + 4 kg DM of harvested FB bulbs (FBB). Dry matter intake (DMI) was similar between H and FBB (15.0±0.77 and 14.2±0.48 kg DM/day respectively). Although milk yield tended to be greater for H than FBB (20.0 and 18.9 kg/ day respectively; P=0.09); milk solids production was not affected by treatment (P=0.89). Supplementation with FBB increased the saturated (80.6 versus 73.2±0.39 g/100g FA; P<0.001) and medium chain milk FA (66.7 versus 56.2±0.783; P<0.001) content, compared with H. Under the conditions of the present study, our results suggest that, supplementing grazing dairy cows with FBB in early lactation, may not improve milk production and increases the saturated FA content of milk.

Pasture use and management in commercial equine production systems - Rogers CW; Gee EK; Back PJ; van Zon S; Hirst RL; Pomroy WE (New Zealand Journal of Animal Science and Production, 2018)
Despite a perceived reliance of horses on pasture there are limited data on efficiency of pasture utilisation in equine production systems. The unique equine behaviour characteristics of highly selective browsing, combined with faecal avoidance, provide distinct grazing management challenges compared to those of ruminants. Data reported here show that faecal avoidance results in the establishment of lawns and roughs (overgrazed and poorly grazed areas, respectively) with it estimated that only 70% of the total pasture DM/ha on offer is utilised by horses. During spring, lawns contained more grass (74% vs 53%) and clover (5% vs 3%) and less weeds (2% vs. 11%) and dead matter (19% vs. 33%) than did roughs. Weanlings will start to graze roughs once the lawns are <1500 kg DM/ha. Roughs, however, will not be grazed within 1 m of a faecal pile. This translates to a lower pasture utilisation rate in weanlings and the biased grazing pattern means estimates of total pasture DM over-estimate the true available pasture DM. The relative proportion of pasture in lawns and roughs changes during grazing and prevents the application of a simple correction factor to estimate available DM. Broodmares had greater rates of pasture utilisation and less bias for consumption of pasture in areas of roughs than did weanlings.

Phenotypic correlations of milk urea and the efficiency of crude protein utilization with milk yield traits and cow performance in two contrasting dairy systems in New Zealand - CorreaLuna M; Lopez-villalobos N; AlmeidaJr GA; Donaghy DJ; Kemp PD (New Zealand Journal of Animal Science and Production, 2018)
The objectives of the present study were to investigate phenotypic correlations of milk urea (MU) and efficiency of crude protein utilization (ECPU) with milk production and cow parameters in two contrasting herds. Between July 2016 and May 2017, 210 cows were milked twice daily with high supplementary feed inclusion (HS) and 258 cows were milked once daily with low supplementary feed inclusion (LS). In early, mid and late lactation, milk samples were collected to measure MU. At every herdtest date, ECPU was calculated as protein yield (PY) divided by crude protein intake (CPI); this last variable derived from intake estimations of metabolizable energy requirements. Positive correlations between milk yield (MY) and both dry matter intake (DMI) and CPI were observed in LS and HS. The ECPU only correlated positively with MY traits in LS, and there was no correlation of CPI with MU in either herd. A moderate negative correlation of ECPU with live weight (LW) was observed in both herds, but it was stronger in LS. By suppressing MY due to the reduced milking frequency of cows fed LS, these cows gained LW, had higher body condition score and CPI, and lower PY, reducing the ECPU. No correlation between ECPU and MU was detected.

Plantain: It is not only the dietary content, but also how we graze it… - Gregorini P; Bryant RH; Beck MR; Edwards GR (New Zealand Journal of Animal Science and Production, 2018)
A mechanistic and dynamic model of a grazing ruminant, MINDY, was used to explore the effect of both the proportion dietary inclusion of plantain (PL) and its grazing management, compared with ryegrass (RG), on urinary N (UN) excretion of dairy cows. The treatment tested were: 1) frequency of allocation and 2) dietary proportion of PL. Frequency of allocation was set by stripgrazing (24 hrs. pasture breaks) PL or RG monocultures for 1, 5 or 10 consecutive days, allocated either after the morning (AM) or afternoon (PM) milking. The proportion of dietary PL was set by offering either 25 or 50% of the diet as PL monocultures allocated either AM or PM. MINDY had greater intake of PL-containing diets than RG alone, resulting in increased N intake. However, with the exception of the ‘frequency’ treatments, daily urinary N excretion (UN) was reduced by including PL compared with RG alone. Plantain monocultures led to similar or lower urine volume compared with RG. Grazing RG and PL every 1 or 5 days increased urine volume, frequency and UN compared with RG or continuous PL. Offering PL or RG in the AM compared with PM reduced UN but reduced milk yield. This modelling exercise suggests that including PL in cattle’s diet reduces UN and UN concentration, and that the frequency and timing of its allocation help to reduce environmental impact further while maintaining or increasing MS.

PRESIDENTS ADDRESS 2018: Moving the cheese - Schreurs NM (New Zealand Journal of Animal Science and Production, 2018)

Reproductive performance of pregnant red deer hinds fed swede forage-crops in winter - Thompson BR; Stevens DR; Petit MA; Asher GW (New Zealand Journal of Animal Science and Production, 2018)
Reproductive wastage is a significant cause of productivity loss in New Zealand deer herds. This study investigated the impact on reproductive performance of red deer hinds fed swedes over winter. Forty rising-two-year-old and 40 mixed-aged pregnant hinds were drafted into two groups each and grazed for 100 days over winter on either a swede forage crop or pasture. Hinds were blood sampled regularly, weighed fortnightly and pregnancy scanned monthly. Blood samples were analysed for blood urea nitrogen and indicators of liver damage. Swede forage crops were sampled for nutrient and glucosinolate concentrations. No significant differences in hind foetal loss were found between the two wintering systems or two age classes. Swede glucosinolate concentrations levels were above thresholds considered dangerous for animal consumption but no liver damage was observed. Blood urea nitrogen levels did not differ between the swede- and pasture-fed hind groups until day 80, which was 10 days after the swede groups were transferred to another swede crop, when blood urea nitrogen levels were significantly lower in the swede groups. This research indicated that grazing on swedes did not influence reproductive wastage in this instance. However, the effect of low protein intake over an extended period during pregnancy needs to be investigated further.

The role of curding and non-curding calf milk replacers in NZ calf-rearing systems - Thomson BC; Muir PD; Smith NB; Nieuwenhuis A (New Zealand Journal of Animal Science and Production, 2018)
Calf milk replacers (CMRs) are typically formulated from a range of lower-value milk products and may have reduced curding ability when casein proteins are absent or denatured. Whilst there are industry claims that vealer calves in Europe can be reared on such CMRs, there is no NZ data to substantiate these claims. In Experiment One, 240 calves were reared on three milk replacers. Diet A was a curding CMR based on whole-milk powder and skim-milk powder. Diet B was a non-curding CMR based on whey and vegetable fat. Diet C was a non-curding CMR based on whey, soy and vegetable fat. A salmonella challenge occurred in the rearing facility during the first two weeks of rearing. Calves on Diet A suffered a much lower incidence of sickness than those on Diets B and C (15% vs 34% vs 61%) respectively. Mortality was also lower (1.25% vs 5% vs 5% respectively). In Experiment Two, 90 calves were fed on the same diets from four days to 13 weeks of age. There were no effects of diet on disease or mortality. Calves on Diet A, B and C had growth rates to 13 weeks of 0.63, 0.60 and 0.53 kg/day, respectively. In conclusion, rearers need to be aware that there a risk when feeding non-curding milk replacers to young calves, particularly when timely weight targets need to be achieved.

The role of pasture and silage in supporting milk production in dairy goats in New Zealand – a case study approach - King W; Burggraaf V; Mapp N; Ganche E; Hutchinson K; Johnson M (New Zealand Journal of Animal Science and Production, 2018)
Milk production on dairy goat farms in New Zealand is highly variable: the average is around 75 kg total solids/doe/year with a range of 39-135 kg total solids/doe/year. The source of variability in production is unclear but is potentially due in part to the diversity in forage-supply systems used by dairy goat farmers. The majority of milking herds that supply the Dairy Goat Cooperative are housed indoors for health and production reasons and are fed a mix of freshly-cut pasture and silage in a cutand- carry system with the addition of concentrates and other supplemental feeds when required. To determine how pasture and silage were used in dairy goat feeding systems, four farms were enrolled in a case study approach. Estimates of the quantity of pasture and silage fed were made and samples were taken and analysed for quality periodically over a one-year period. Results showed that pasture quality generally followed the expected seasonal curve for the Waikato. Pasture quality declined from about 12.5 MJ ME/kg DM in early spring to 11 MJ ME/kg DM or less in December and was largely unavailable from March. At this time, silage becomes a much more important component of the feed-supply system. The quality of the silage was, however, variable with dry matter content, metabolisable energy and crude protein (CP) levels sometimes outside recommended limits. Total diets were deficient in nutrients at some times on some farms, especially with respect to protein. A comparison of calculated feed requirements with what was actually fed showed that protein was deficient in six of the twelve sample periods, by up to 211 g of CP/doe/day. These deficits were associated with lower milk production. This study highlighted the potential for higher milk production from maintaining both pasture and silage quality.

Simulating the intake and nitrogen excretion from cows grazing forages fertilised with increasing rates of nitrogen - Minnee EMK; Bryant RH; Chapman DF; Gregorini P (New Zealand Journal of Animal Science and Production, 2018)
The dry matter intake (DMI), production, and urinary nitrogen (N) excretion of dairy cows grazing forage grown under increasing N fertiliser rates were explored using a mechanistic model of a grazing ruminant. The MINDY cow model was initialised to represent a multiparous Holstein-Friesian dairy cow in late lactation (age 3.5 years, 212 days in milk). Simulated cows were offered a common allowance (30 kg DM/cow/d) of chicory, plantain, lucerne, or perennial ryegrass, fertilised at rates of 0, 100, 200, 350 and 500 kg N/ha/y (0N, 100N etc.) for 20 days in March. Forage physical and chemical composition data were obtained from a Waikato experimental field site. When N rate increased from 0–500N, predicted DMI of cows grazing plantain and ryegrass increased by 5.2 and 2.7 kg DM/cow/day (43 and 20% increase), respectively, facilitated by increased sward height and mass, and reduced herbage strength. Predicted DMI of cows grazing chicory peaked at 200N and, for cows grazing lucerne, declined with N fertilisation. Intake of highly fertilised (>200N) chicory and lucerne diets were potentially affected by high herbage soluble N content resulting in high predicted rumen ammonia concentrations (>18 mmol/L), reducing incentive for grazing. While predicted milk production from cows grazing chicory, plantain and ryegrass increased, the efficiency of dietary N used for milk production declined, with increasing N applied. Increasing N rate also increased predicted urine N concentration, and urinary N excretion from simulated cows fed chicory, plantain, and ryegrass. This study suggests that N fertiliser rates of 200N for chicory, plantain and ryegrass provides a balance between cow production and N excretion.

Supplementation of ewes on pasture to provide an epidemiological benefit for gastrointestinal parasitism - Tambunan RD; Logan CM; Bywater AC; Greer AW (New Zealand Journal of Animal Science and Production, 2018)
The potential epidemiological benefit of reducing the peri-parturient relaxation in immunity to gastro-intestinal nematode parasites through supplementing twin-bearing ewes during the first four weeks of lactation was evaluated in a replicated farmlet study. In two sequential years, ewes either grazed pasture alone or grazed pasture while supplemented with 0.5 kgDM/d of a high-protein pellet. Supplementation did not affect ewe live weight or body condition score or weight of lamb weaned per ewe (P>0.05). Ewe faecal egg counts (FEC) showed a time x supplementation interaction (P<0.05), being reduced by 50% from week six of lactation in both years, although this only resulted in transient and inconsistent reductions in pasture larval contamination. After weaning, there was no consistent parasitological benefit to lambs grazing areas where ewes had been supplemented that were reflected in either pasture larvae concentrations, lamb FEC, the requirement for anthelmintic treatment or lamb growth rate (P>0.05 for all). Despite supplementation of ewes during the first four weeks of lactation successfully reducing ewe faecal egg count by 50%, this was not sufficient to provide a measureable and consistent epidemiological benefit to the lambs.

To train or not to train heifers to the milking parlour prior to calving? That is the question for New Zealand dairy farmers - Sutherland M; White T; Chen K; Hempstead M; Huddart F (New Zealand Journal of Animal Science and Production, 2018)
A survey was conducted to identify: 1) the number of dairy farms that train their heifers to the milking parlour prior to calving, 2) the reasons why farmers chose to train or not and 3) what training methods farmers use. The questionnaire was sent to 250 randomly selected dairy farmers within New Zealand. Of the 93 respondents, 52% trained their heifers to the milking parlour prior to calving and 48% did not. Of those that trained, 79% trained to reduce stress levels, 13% to increase milk production and 19% to reduce risk of injury to animal/farmer. Conversely, of the farmers that did not train their heifers to the milking parlour prior to calving, 56% reported that “cows teach the heifers”, 24% reported that they were too busy and 31% indicated that training did not work. The main methods of training included walking heifers through the milking parlour, holding heifers in the parlour and exposing them to people. The results from this survey provide interesting information regarding the motivation of farmers to train (or not train) heifers to the milking parlour prior to calving and what training methods are used. Information gained from this survey can inform the direction of future research so that science-based farmer friendly recommendations for heifer training can be developed.

Whole-farm modelling using different grazing-management strategies with diverse pastures within an irrigated dairy-farm system - Cun, GS; Al-marashdeh O; Edwards GR (New Zealand Journal of Animal Science and Production, 2018)
The objective of this study was to assess the effect of diverse pasture mixtures and grazing management on profitability of Canterbury dairy farms using a commercial modelling tool, Farmax Dairy Pro. Two years of pasture growth and quality data were obtained from irrigated plots sown with a pasture mixture consisting of perennial ryegrass, white clover, red clover, chicory and plantain (diverse) or the same pasture mixture plus Italian ryegrass (diverse-Italian). Pastures were subjected to one of three grazing management regimes: (1) conventional grazing (grazed to a compressed height of 3.5 cm all year); (2) spring lenient grazing; and (3) autumn lenient grazing. The data were fitted to a base model farm (average of North Canterbury region) using Farmax Dairy Pro to produce six different farm scenarios. Farm scenarios were ranked and compared by profit expressed as earnings before tax. Pastures managed by autumn lenient grazing resulted in the lowest DM production, more supplement purchased, and hence, lowest profit compared with conventional or spring lenient grazing management. The diverse pasture managed by spring lenient grazing resulted in the greatest profit ($2,658/ha) compared with other scenarios (average $2,261/ha). This greater profit was driven by greater annual DM production per hectare and, hence, less supplement purchased. When diverse pasture is considered, spring lenient grazing is a potential management option for irrigated Canterbury dairy farm systems to increase DM production and thereby profitability.

Abstracts from the Sheep Milk NZ Conference - Awapuni Function Centre March 3-15 2017 - Anonymous (Proceedings of the New Zealand Society of Animal Production, 2017)

BRIEF COMMUNICATION: An investigation of mastitis in a hill-country sheep flock - Peterson SW; Nieper B; Collett MG; Grinberg A (Proceedings of the New Zealand Society of Animal Production, 2017)
The prevalence of mastitis in New Zealand ewes has not been studied for over 40 years. Quinlivan (1968a,b) examined 19427 Romney ewes in the lower North Island and detected mastitis in 0.6-1.7%. Clarke (1972) surveyed 118249 ewes in the lower South Island and found the incidence of mastitis was 0.6-0.7%. Skyrme (1970) reported the occurrence of “hard udders” and implicated them in lamb deaths. Perhaps because of such reports of low incidence, little research into sheep mastitis has been done in New Zealand...

BRIEF COMMUNICATION: Assessing the current value of milk, meat and fibre products from the goat industry in New Zealand - Lopez-Lozano SR; Scholtens MR; Smith RMC; Lopez-Villalobos N; Burt D; Harper L; Thomas DG; Carr AJ; Gray DI; Tozer P; Schreurs NM (Proceedings of the New Zealand Society of Animal Production, 2017)
Goats have a historical record of being productive and valuable to families and communities (Aziz 2010). Small ruminants, which include goats, still have an ‘unfulfilled’ potential despite the numbers of animals farmed and their distribution around the world (Anaeto et al. 2010). Pollot and Wilson (2009) concluded that goats deserve greater attention due to their capacity for producing food. A similar study in New Zealand (Sheppard & O’Donnell 1979), described the uses of goats for meat, skins, milk and mohair and concluded that the goat was valuable, but that the production potential was largely unfulfilled. A recent New Zealand study (Ministry of Agriculture and Forestry 2009) concluded that food-consumption patterns are changing in New Zealand, and globally demand for more diversified products provided an opportunity for goat meat. The objective of this study was to determine the current value of domestic and exported New Zealand goat products and to explore possible future products and their target markets. Many of these product values are gathered from retailers, personal communications and individual producers. This research is an attempt to bring together information that has not yet been gathered to present a current value of the goat in New Zealand...

BRIEF COMMUNICATION: Effect of disbudding on pain sensitivity and weight-gain of dairy goat kids - Hempstead MN; Stewart M; Sutherland MA (Proceedings of the New Zealand Society of Animal Production, 2017)
Cautery disbudding is a painful husbandry procedure commonly carried out on dairy cow and goat farms worldwide. Disbudding can cause third-degree burns, subcutaneous tissue damage, inflammation, bacterial infection and in some cases death (Sanford 1989, Thompson et al. 2005, Wright et al. 1983). Physiological (e.g., cortisol, β-endorphins) and behavioural (e.g., head shaking) changes indicative of pain have been described in response to cautery disbudding in kids (Alvarez et al. 2015, Greenwood & Shutt 1990, Ingvast-Larsson et al. 2011), but still little is known regarding the acute and long-term effects of cautery disbudding on goat kid welfare. Therefore, the aim of this study was to evaluate the effects of cautery disbudding on the acute pain response and weight-gain in goat kids. This study was part of a larger project investigating alternative methods of disbudding in goat kids.

BRIEF COMMUNICATION: Efficiency of crude protein utilization and milk urea nitrogen content in Friesian, Jersey and crossbred cows milked once daily - CorreaLuna M; Lopez-Villalobos N; Donaghy DJ; Kemp PD; AlmeidaJr GA (Proceedings of the New Zealand Society of Animal Production, 2017)
For the last two decades, the New Zealand dairy industry has intensified its milk production through the inclusion of feed supplements and the increasing use of nitrogen (N) fertilizer (Di & Cameron 2000). Increasing N losses from these systems, mainly from urine (Li et al. 2012), can negatively impact the environment. Cow N utilization efficiency can play a role in mitigating this negative effect (Woodward et al. 2011)...

BRIEF COMMUNICATION: Feeding fodder beet to ewes in mid-to-late gestation: impact on lamb size, rectal temperature, and live weights from birth to weaning - Sandoval E; McCoard SA; Pacheco D; Lloyd-West C; Lees S; Hammond KJ (Proceedings of the New Zealand Society of Animal Production, 2017)
New Zealand ruminant livestock production is largely pasture-based and aligned to seasonal pasture supply. Despite pasture providing a complete diet for grazing pregnant ewes when fed in sufficient quantities, there is a growing trend for farmers to use supplementary feeds to maintain production in times of feed shortages such as during winter, or to facilitate increased stocking rates (McCoard et al. 2015). Due to its high dry matter (DM) yield, and low cost per unit of feed, compared to other supplementary feeds (Gibbs et al. 2015), fodder beet (FB: Beta vulgaris) is a winter feed option. Fodder beet is characterised by its high sugar (energy rich) and low nitrogen (N) contents and although live weight (LWT) responses in finishing beef cattle fed FB have been measured (Gibbs et al. 2015), there is less knowledge on the nutrient-supply profile and performance of offspring when fed to pregnant animals. Knowledge of potential nutritional deficiencies, and the implications for the pregnant ewe and her offspring are essential in order to develop feeding recommendations for farmers. The objective of this study was to determine the effects of feeding FB vs. ryegrass dominant pasture (RG), to ewes in mid-to-late gestation, on offspring performance through the measurement of lamb size, rectal temperature and pre-weaning growth.

BRIEF COMMUNICATION: High ultimate pH in short-scrotum male lambs processed during the breeding season - PL Johnson; Stuart AD; Mackie A (Proceedings of the New Zealand Society of Animal Production, 2017)
Historically in New Zealand male lambs were castrated at the time of docking, however, there has been a move to instead create short-scrotum males, in which the testes are pushed within the body cavity and the scrotum removed (Johnson et al. 2007). This results in short- scrotum males, having similar physiological characteristics to entire ram lambs, except that they are almost always infertile and, therefore, do not present a management risk if they are accidently mixed with ewes or ewe lambs during the mating season. The normal ultimate pH of lamb meat is considered to be 5.50 to 5.80, with values above 5.8 and in particular above 6.0 considered high, and resulting in negative meat quality outcomes. There have been a number of studies that have investigated whether or not sex differences in the ultimate pH of lamb exist. The results are not always consistent with some studies reporting elevated ultimate pH in non-castrated male lambs (Johnson et al. 2005; Bain et al. 2009), whilst others have shown no differences (Kerslake et al. 2012; Schreurs 2013). In commercial farming operations there is a mix as to how farmers manage their lambs of different sexes during the finishing period prior to slaughter, and in many farming operations this period coincides with the on-set of the breeding season. Given the most recent papers in this area have concluded that there is no sex-effect on ultimate pH, the purpose of this paper is to report on data collected from a trial that set out to invoke high ultimate pH (to investigate potential live-animal predictors of high ultimate pH) in short-scrotum male lambs during the breeding season.

BRIEF COMMUNICATION: Hot years in history and facial eczema - PL Johnson; Cameron CA; Henderson HV; Cullen NG (Proceedings of the New Zealand Society of Animal Production, 2017)
Facial Eczema (FE) is caused by grazing animals ingesting the toxin sporidesmin which is produced by spores of the fungus Pithomyces chartarum. In order for the fungus to sporulate, a series of weather and environmental events must occur, with warm, moist, humid conditions and leaf dead-matter at the pasture base required (Brook 1969). In New Zealand, the combination of required conditions has historically been confined to summer and autumn months in temperate parts of New Zealand as illustrated in a map published by di Menna et al. (2009). There is a large body of research that concludes that the world is in a period of climate change, characterised by increasing temperatures and extreme weather events (Ministry of Environment NZ, 2008) with the temperature increases predicted to incrementally increase into the future. Using climate change predictions, modelling work reported by di Menna et al. (2009) and Dennis et al. (2014) demonstrated that into the future the geographical regions in New Zealand affected by FE would increase, as temperature increases would result in more areas achieving the minimum temperatures required for sporulation. Through using published literature and media articles prior to 2016, the worst years for FE in New Zealands history were 1938 and 1999. Indeed the outbreak in 1938 was what led to the establishment of the Ruakura Research Centre (now AgResearch) in an attempt to understand the cause and control of the then-unknown disease that had resulted in photosensitivity, liver damage, production losses and death in affected animals (di Menna et al. 2009). The purpose of this paper is to report on the FE outbreak of 2016 and to draw temperature parallels to the outbreaks of 1938 and 1999 using weather data from the Ruakura Weather Station.

Brief Communication: In vitro fermentation characteristics of ryegrass-white clover sward containing differnt proportions of chicory - Al-marashdeh O; Cheng L; Gregorini P; Edwards GR (Proceedings of the New Zealand Society of Animal Production, 2017)
Chicory (Cichorum intybus) is a deep-rooted grazeable forage used to overcome production and nutritive value shortfalls of perennial ryegrass (Lolium perenne) and white clover (Trifolium repens) swards during summer drought periods in New Zealand (Waugh et al. 1998; Chapman et al. 2012). However, there is little and contrasting data on the proportion of chicory to be used in mixed swards to influence livestock production. For example, Golding et al. (2011) showed that feeding chicory in a mixed sward at 18–40% of total dry matter, increased lamb post-weaning liveweight gain (LWG) compared with a traditional ryegrass sward. On the other hand, Cheng et al. (2017) reported similar daily LWG for heifers offered a mixed sward of 50% chicory and 50% ryegrass-white clover or 100% perennial ryegrass-white clover. These contrasting results justify more research on the chicory proportion in mixed swards and its effect on animal performance...

Brief Communication: Managing liveweight gain of Holstein-Friesian, Jersey and Holstein- Friesian-Jersey crossbred heifer calves - Back PJ; Hickson RE; Sneddon NW; Coleman LW; Laven RA (Proceedings of the New Zealand Society of Animal Production, 2017)
Large numbers of replacement heifers are not meeting target live weights in New Zealand (McNaughton & Lopdell 2012; Handcock et al. 2016) which has implications for future milk production, fertility and subsequent longevity in the herd (Van Amburgh & Tikofsky 2001; McNaughton & Lopdell 2013). Undergrown heifers can lead to an overall decline in a herd’s reproductive performance and milk production (McNaughton & Lopdell 2012). McNaughton and Lopdell (2013) reported that for every 1% increase in the percentage of live weight attained, heifers produced approximately 23 litres of extra milk during their first two lactations. As such, heifer growth, particularly post-weaning growth, has been identified as an area requiring greater attention from farmers to improve cow performance. There are established breed liveweight targets as well as liveweight targets based on an individual animals genetic potential and the growth of individual animals and groups can be monitored using programmes such as Livestock Improvement Corporation’s MINDA Weights™ herd-recording software. However, while growth targets are commonly used, in many cases, being ‘on-target’ is based on a mob average, resulting in a proportion of animals below target live weight....

BRIEF COMMUNICATION: Once-a-day milking with supplemented cows in Argentina - Lazzarini B; Peluffo L; Lopez-Villalobos N; Hendrikse L; Baudracco J (Proceedings of the New Zealand Society of Animal Production, 2017)
Dairy farming is an important activity in Argentina. The country produced over 11,000 million litres of milk in 2015 (Ministerio de Agroindustria 2015). Milk production is based on the utilisation of grazed lucerne pastures (Medicago sativa L), and the use of supplements such as silage, hay and concentrate feeds. Pasture comprises between 30% and 50% of the diet. Average milk production per cow is 5,900 kg/cow per year (equivalent to 401.2 kg of milk solids/cow per year; INTA 2015). Due to a favourable ratio between milk price and concentrate feeds price (average ratio milk to concentrate price over 1.5), dairy farmers in Argentina include great amounts of concentrate feeds in their systems. Over 95% of dairy herds of Argentina are Holstein, and cows are milked twice a day (TAD) (FAO 2011). In the last decade, studies have been conducted, mainly in New Zealand, but also in Europe, to evaluate the effects of once-a-day (OAD) milking during the whole lactation (Stelwagen et al., 2013). Lifestyle benefits for farmers and employees and improvement in animal health and reproductive performance are the main motivations to choose OAD milking (Bewsell et al., 2008)...

BRIEF COMMUNICATION: Reduced reproductive outcomes in ewes susceptible to facial eczema - PL Johnson; Henderson HV; Proffit R; Cullen NG (Proceedings of the New Zealand Society of Animal Production, 2017)
There are both clinical and sub-clinical effects on grazing ruminants that ingest the toxin sporidesmin produced by the fungus Pithomyces chartarum, with the clinical effects of the toxin giving rise to the colloquial name of the disease “facial eczema”. The sub-clinical effects of Facial Eczema (FE) have been documented and impact on most aspects of production from fertility through to growth. Data used to estimate the effects of the sporidesmin ingestion have ranged from natural exposure to high levels of sporidesmin in the outbreak in 1981 (Moore et al. 1990) through to differences in genetic selection lines and in trials where animals are artificially dosed with sporidesmin (Morris et al. 1991). Whilst the size of the impact does vary between studies, their overall conclusions are consistent, with decreased ewe fertility observed. In all studies, how the animal has tolerated (or not) the sporidesmin that it has been exposed to, is estimated through measuring serum gamma-glutamyl transferase (GGT) levels which have been shown to be a strong indicator of liver damage, the body organ most directly affected by the toxin (Towers & Stratton, 1978)...

BRIEF COMMUNICATION: Relationship between measures of residual energy intake made on growing animals and adults - PL Johnson; Wing J; Knowler K (Proceedings of the New Zealand Society of Animal Production, 2017)
In New Zealand pasture-based sheep systems, young replacement ewe lambs and those lambs to be finished for slaughter, are often preferentially fed through summer, with ewes which have just weaned their lambs given secondary priority through until their pre-mating period. This is particularly the case in hill-country environments, in which an increasing proportion of the New Zealand ewe flock is farmed. Feed efficiency, defined as residual energy intake (REI), is a measure of whether or not an animal is eating more or less than expected for its live weight and growth rate. Of interest is whether or not animals described as efficient, or inefficient during their young growth phase, when on high-quality diets, continue to be so as an adult grazing sub-optimal feed during summer periods. There is limited comparable literature in sheep. The general finding of the beef cattle work is that the young and adult measures of REI are moderately phenotypically correlated and very highly genetically correlated, although in the most comprehensive study both the young and adults were fed the same medium-quality feed (Archer et al. 2002). In dairy cattle work, they have also found that calves divergent for REI during growth are also divergent for REI when lactating, although the size of the divergence was reduced (McDonald et al. 2014)...

BRIEF COMMUNICATION: The current state of the New Zealand goat industry - Scholtens MR; Smith RMC; Lopez-Lozano SR; Lopez-Villalobos N; Burt D; Harper L; Tuohy M; Thomas DG; Carr AJ; Gray DI; Tozer P; Schreurs NM (Proceedings of the New Zealand Society of Animal Production, 2017)
Goat farming in New Zealand has a lower profile compared to dairy, sheep and beef systems. The goat industry is small in New Zealand (Stafford & Prosser, 2016) and there has been limited consideration of the potential for the industry to expand (Shepard & O’Donnell, 1979). The environmental and commodity market constraints currently impacting pastoral systems in New Zealand provide an opportunity for the goat industry to have a greater economic contribution to New Zealand’s agricultural production. In New Zealand, goats are farmed for milk, meat and fibre production and also act as a mechanism for controlling excess pasture growth, enhancing clover in mixed pasture and controlling weeds (Batten, 2014). The aim of this paper was to present an overview of the goat industry to provide background knowledge for consideration when deciding the direction of the goat industries in New Zealand. As part of the overview, farmers, processors and industry bodies were contacted to obtain an estimate of the number and location of goats farmed in New Zealand. Although some of the sources of information for the goat industry are not perfect, this research is an attempt to bring together information that has not been consolidated in nearly 40 years (Shepard & O’Donnell, 1979) and was achieved as part of a three-part study with companion papers being produced (Lopez-Lozano et al. 2017; Smith et al. 2017). Information from this study were used in conjunction with the value of the goat industry (Lopez-Lozano et al. 2017) to project the potential of the New Zealand goat industry (Smith et al. 2017).

BRIEF COMMUNICATION: The effect of arginine supplementation and milk allowance on small intestinal development in pre-weaning calves - van Keulen P; Welboren AC; Kahn MA; Knol FW; Dijkstra J; McCoard SA (Proceedings of the New Zealand Society of Animal Production, 2017)
The gastrointestinal tract is an organ system crucial in feed digestion, nutrient absorption and protection against external pathogens. In this respect, changes in the structure of the small intestine in pre-ruminant calves are particularly important because it is the primary site of digestion and absorption (Blum 2006). Understanding factors that influence intestinal development is essential to inform calf feeding practices to optimise growth performance and health. Increasing milk allowance increases calf growth, but suppresses solid feed intake before weaning and, therefore, delays rumen development (Khan et al. 2011). In comparison to the rumen, development of the small intestine has received little attention in calf nutrition (Steele et al. 2016) and the effect of increased milk intake on small intestine development in calves is largely unknown (Khan et al. 2016)....

BRIEF COMMUNICATION: The potential of the New Zealand goat industry - Smith RMC; Scholtens MR; Lopez-Lozano SR; Lopez-Villalobos N; Burt D; Harper L; Thomas D; Carr A; Gray D; Tozer P; Schreurs NM (Proceedings of the New Zealand Society of Animal Production, 2017)
The New Zealand goat industry is evolving and there is potential for expansion of its export products. The production and value of the New Zealand goat industry has been explored previously when the industry was in its infancy (Sheppard & O’Donnell 1979), at a time when Mohair production was seen to be ‘the most profitable goat farming enterprise’. Since then major expansion has occurred in the production and export of dairy-goat products, and the production of quality Boer goat meat is under consideration. In order for further progress to be made, knowledge of the current production levels and value of the goat industry, and its potential for expansion is required. Using information describing the current situation of the goat industry (Scholtens et al. 2017) and the value of the goat (Lopez-Lozano et al. 2017), a model was created to estimate the current and potential production and value of the New Zealand goat industry by 2025.

A brief study on the treatment and attitudes to rams on commercial NZ farms - Lee M; Robertson D (Proceedings of the New Zealand Society of Animal Production, 2017)
A study was undertaken to better understand the care and attitudes towards rams on NZ commercial farms. Farms (n=22) were surveyed in Otago and South Canterbury giving indicative data on the treatment and attitudes that commercial farmers have towards rams. On average (SD; Range) the number of ewes put to each ram was, for maternal and terminal sires respectively, 92 (21; 56-143) and 84 (20; 50-100). The reported difference between when rams were put to ewes and when lambs were weaned was 319 days (51; 199-359). Rams were typically put to ewes in April and early May, and weaned as early as November. Visual assessment was most commonly used to assess rams for purchase, with most farmers considering visual attributes and then figures, such as breeding values, to choose rams. The average mortality of rams was reported as 5% (7%; 0-28%). The average culling of maternal and terminal sires over the year was respectively 26 and 29%. Annual health checks by a vet were reported for 45% of the farms. A most common reason for checking was for Brucella ovis testing. This research will provide information to guide further studies on commercial sheep farms.

Calf and heifer development and the onset of puberty in dairy cows with divergent genetic merit for fertility - Meier S; Fisher B; Eketone K; McNaughton LR; Amer PR; Beatson P; Bryant JR; Dodds KG; Spelman R; Roche JR; Burke CR (Proceedings of the New Zealand Society of Animal Production, 2017)
A research herd with divergent genetic merit for fertility was established to better understand the underlying drivers of fertility in dairy cattle. This paper describes the establishment of this herd, heifer growth and development, and the effect of divergence in fertility breeding value (FBV) on the timing of puberty. The average FBV of the high and low fertility groups of heifers was +5.6 and -4.6, respectively. The heifers were weighed fortnightly, with body condition score (BCS) and stature recorded at six, nine, 12 and 15 months of age. Weight and age at puberty were defined as the first day when plasma progesterone was >1 ng/ml in two of three consecutive once weekly samples. There was no effect of FBV on live weight (LWT), BCS, nor stature by age as the heifers matured. High-fertility heifers attained puberty at a lighter LWT (271 vs. 296 kg; SED 4.3 kg), an earlier age (358 vs. 379 days; SED 6.0 days) and a lower proportion of estimated mature LWT (51 vs. 55%; SED 0.7%), compared with Low-fertility heifers. Therefore, the premise that high genetic merit for fertility is positively associated with reaching puberty earlier is supported. Further work is required to support and assess the value of incorporating a puberty trait into the FBV.

Can Raman spectroscopy predict beef meat and eating quality traits? - Fowler SM; Schmidt H; Hopkins DL (Proceedings of the New Zealand Society of Animal Production, 2017)
Quality assurance and guaranteeing meat and eating quality continues to be an ongoing challenge to red meat processors, as many measures of meat quality require resource intensive, destructive or subjective tests. Consequently, there is a need to develop rapid, non-invasive and non-destructive methods for meat quality assessment in commercial processing plants. Therefore, a preliminary investigation was conducted to determine the potential for a hand-held Raman spectroscopic device to predict meat quality and sensory traits measured by an untrained consumer panel. To this end, 45 beef loins (m. longissimus thoracis) were measured using a 671nm hand-held Raman spectroscopic device. Once spectra were collected, loins were frozen until sensory testing and shear force measurements. Further sub-samples were also collected to measure traits including sarcomere length, particle size, pH and colour. Derived models indicate that using Raman spectra it was possible to predict juiciness and tenderness, with cross validated correlations between the predicted and observed values (R2cv) of 0.42 (RMSEP = 11.29) and 0.47 (RMSEP = 10.52). A tentative band assignment suggests that these predictions may be based on changes to the biochemical characteristics of the muscle asso-ciated with hydrophobicity of proteins, fatty acid composition and the collagen matrix. However, further research is required to determine the repeatability and robustness of these models on a larger independent data set.

Changes in rumination behaviour after abrupt or diluted-milk weaning methods in goat kids - Freeman HBR; Webster JR; Zobel G (Proceedings of the New Zealand Society of Animal Production, 2017)
Rumination development is vital during weaning, when kids are transitioning from a reliance on milk to hard feeds. This study analysed rumination behaviour prior to, and following, two weaning methods: abrupt milk removal, and dilution of milk with water; both are common weaning practices on farm. We hypothesised that the dilution weaning method would better prepare kids to cope with the transition to full rumination. Thirty, 13-week-old Saanen cross goat kids were housed in pens of five. Two kids were nominated, for observation, from six pens (n=6/treatment). Kids had free choice access to hay, straw, water and a pelleted ration. Rumination behaviour was continuously recorded for two 24 h periods, before weaning and after weaning. Weaning treatment had no effect on rumination behaviour, though, both daily rumination time and number of boli regurgitated increased following weaning (3.6 vs. 5±0.4 h/d, and 289 vs. 403±29 boli/day). Rumination may be unaffected by using either weaning method, provided the kids have had access to forages and are not weaned too early. Early development of rumination allows kids to cope with milk removal and the switch to solid food, and quantifying its development is important to create best practice guidelines for the weaning period.

A comparison of faecal sample collection times for estimating faecal output and total tract digestibility using inert markers in sheep offered three ryegrass cultivars at two allowances - Jonker A; Cosgrove GP (Proceedings of the New Zealand Society of Animal Production, 2017)
The objective of this study was to compare different faecal sampling regimes (collected in the morning (am) or the afternoon (pm), or the weighted mean of both times) for determining the concentrations of faecal markers (the natural odd-chain n-alkanes (C27 – C35) contained in feed, the dosed (once daily in the morning) synthetic n-alkanes (C32 and C36) and titanium dioxide (TiO2)) and their accuracy for estimating dry matter digestibility (DMD) and faecal dry matter (DM) output from wethers (n = 30) fed cut ryegrasses. The concordance correlation coefficient (CCC) with measured faecal DM output was strong (CCC = 0.8) for faecal DM output predicted from the mean concentration of C32 in morning and afternoon faeces (am+pm), moderate (CCC = 0.6-0.7) when predicted from TiO2 am and am+pm, and weak when predicted from C36. The DMD predicted by C27 and C33 at either collection time, and by C29 and C31 for samples collected in the pm, were similar to measured DMD. The estimated DMD based on faecal C35 had a negligible CCC with measured DMD (CCC<0.1), while other natural n-alkanes had a low to moderate CCC (0.3-0.6) with measured DMD, especially for the samples collected pm and am+pm. For applications with grazing animals, where marker dosing and faecal sampling is often restricted to once daily in the morning for practical reasons, TiO2 was the most accurate marker to estimate faecal DM output and C31 or C33 were the most accurate and precise markers to estimate DMD.

Comparison of health and reproductive treatments over three seasons for once-a-day and twice-a-day milking herds - Van Der Spek P; Sneddon NW; Lopez-Villalobos N; Donaghy DJ; Laven RA; Mueller KR; Amoore J; Doohan H (Proceedings of the New Zealand Society of Animal Production, 2017)
Once-a-day (OAD) milking has been increasing in popularity in New Zealand, while housing cows is being advocated as one means of minimising environmental impacts of dairying. The present study aimed to investigate health treatments under four different farming systems: OAD, and three twice-a-day (TAD) systems (housed, standard and commercial). There were health records from 377 cows milked OAD and 878 cows milked TAD, over the dairy seasons 2013-14, 2014-15 and 2015-16. Data were analysed assuming binomial distributions for the dependent variables with a generalised linear model that included the effects of season, system (OAD, TAD systems), breed and lactation number. In 2014-15, cows milked OAD were treated less often for mas-titis than cows milked TAD (12% and 25% respectively; P<0.05). Cows milked OAD had fewer reproductive treatments compared to cows milked TAD (standard) in 2014-15 and 2015-16 (1% vs 39% and 2% vs 40% respectively; P<0.01). These results support the advice to farmers that milking OAD does not have a major impact on the risk of mastitis but may provide benefits in terms of reproductive performance. In addition, cows milked TAD (housed) had 13% of the cows treated for lameness compared to 7% of cows milked TAD (standard) (P<0.01).

Contract session: An overview of postpartum hyperketonaemia and its association with cow health and performance in pasture-based dairy systems - Phyn CVC; Kuhn-Sherlock B; Turner S-A; Grala TM; Burke CR; Roche JR (Proceedings of the New Zealand Society of Animal Production, 2017)
Following calving, dairy cows undergo a period of negative energy balance during which they mobilise body tissue (such as fat) to support the demands of lactation. When the negative energy balance is severe, the inability of the liver to process all the mobilised fatty acids can lead to hepatic lipidosis (i.e., fatty liver disease) and incomplete fatty acid oxidation. The latter results in the hepatic production of ketone bodies, predominantly β-hydroxybutyrate (BHB), which are released into the circulation as the product of ketogenesis. The increased concentration of ketones in blood is known as hyperketonaemia...

Contract session: BVD bulk milk testing - Lowe AD (Proceedings of the New Zealand Society of Animal Production, 2017)
Bovine Viral Diarrhoea (BVD) is a highly prevalent and infectious viral disease found in cattle in New Zealand, and in many other countries around the world. It is a widespread disease and it is estimated that up to 60% of NZ dairy and beef cows have been exposed to BVD (BVD Steering Committee 2017, http://www.controlbvd.org.nz). The BVD virus (pestivirus) has damaging effects on the health, reproductive performance, growth, and productivity of a dairy herd and sometimes causes death. The production losses are significant; estimated annual losses for NZ dairy farmers are around $127 million. The cost for our beef farmers is around $3000-$9000 per 100 cows in infected herds (BVD Steering Committee 2017, http://www.controlbvd.org.nz). BVD is a serious threat to our farmers, but also to New Zealand’s economy...

Contract session: Caprine arthritis encephalitis in New Zealand dairy goat farms - Pryor SM (Proceedings of the New Zealand Society of Animal Production, 2017)
Caprine arthritis-encephalitis (CAE) is a widespread disease in goats that was first reported in New Zealand in 1981 (Oliver 1982; Oliver et al. 1983). The disease is caused by a lentivirus (CAEV) which, like all retroviruses, inserts its genome into the DNA of the cell it infects. CAEV infects and replicates within monocytes and macrophages and these immune cells then carry the virus throughout the body. Seroconversion typically occurs slowly (months rather than weeks) and there is no simple relationship between the initial infection and moment of conversion. All breeds and ages of goats are susceptible to infection and, once established, it persists throughout the animal’s life. Progression of the disease can take months to years and it is unusual to observe gross clinical signs prior to two years of age. Not all goats that are infected with CAEV will develop the disease and these asymptomatic carriers may spread the disease within the herd. The most common symptom of CAE is chronic arthritis in adult animals. Bilateral or unilateral swelling of the carpal region is common, hence the lay term ‘big knees’. Infection can also lead to weight loss and/or impaired milk production (Greenwood 1995). The major transmission route of CAEV is through the ingestion of virus-infected colostrum by kids, although lateral transmission through prolonged close contact with infected animals is also thought to occur (Adams et al. 1983) and, more recently, evidence suggests that vertical transmission from the reproductive tract of infected females to their offspring is possible (Hasegawa et al. 2017). CAEV has been found in semen, so it is also possible that a doe may get the disease from an infected buck (Souza et al. 2013).