@article {3672, title = {Changes in live weight and fleece characteristics during the lifetime of three breeds of New Zealand feral sheep that differ in fleece type}, journal = {New Zealand Journal of Animal Science and Production}, volume = {80}, year = {2020}, month = {09/2020}, pages = {117-123}, address = {Online}, abstract = {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{\textquoteright}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}, issn = {1176-5283}, author = {Sumner RMW and Scobie DR and O{\textquoteright}Connell D and Henderson HV} } @conference {3672, title = {BRIEF COMMUNICATION: Hot years in history and facial eczema}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {107-109}, address = {Rotorua}, abstract = {

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.

}, issn = {1176-5283}, author = {PL Johnson and Cameron CA and Henderson HV and Cullen NG} } @conference {3672, title = {BRIEF COMMUNICATION: Reduced reproductive outcomes in ewes susceptible to facial eczema}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {77}, year = {2017}, month = {06/2017}, pages = {197-199}, address = {Rotorua}, abstract = {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 {\textquotedblleft}facial eczema{\textquotedblright}. 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)...}, issn = {1176-5283}, author = {PL Johnson and Henderson HV and Proffit R and Cullen NG} } @conference {89244, title = {Association of the KRT33A (formerly KRT1.2) gene with live-weight and wool characteristics in yearing Perendale sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {158-164}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

DNA samples from 691 mixed-sex Perendale sheep, born between 1998 and 2001, were typed for variation in the KRT33A gene using polymerasechain reaction - single-strand conformational polymorphism. The sheep were the progeny of two linesselected for either decreased (L), or increased (H) core bulk at yearling shearing, crosses between the lines and back-crosses. Five variants (A{\textendash}E) of KRT33Awere identified with a frequency of 0.07, 0.04, 0.07, 0.35 and 0.47, respectively. The proportion of Adecreased and Bincreased, with a progressive increase incrimp frequency, fibre curvature and core bulk and a progressive decrease infleece weight, staple length and washing yield with each step-wise increase in the proportion of genes derived fromthe H line. An effect of the presence of Aon the measured wool characteristics was found, but was less than the effect with direct selection for core bulk. There was no consistent effect on body growth. While none of the variants of KRT33Awere strongly predictive of variation in core bulk, other genes on Chromosome 11 may be implicated in the differential expression of characteristics associated withcore bulk.

}, issn = {1176-5283}, author = {Sumner RMW and Forrest RHJ and Zhou H and Henderson HV and Hickford JGH} } @conference {89234, title = {Development of ultrasound methodology to measure cow udder cistern storage capacity in the New Zealand pasture-fed context}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {114-116}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Studies have demonstrated that, for a given amount of secretory tissue, cows with a proportionally larger cistern produce more milk and are more resistant to the inhibitory effects on milk synthesis of longer milking intervals (Knight \& Dewhurst 1994; Stelwagen \& Knight 1997; Davis et al. 1998). This may be because they can store more milk before milk accumulation begins to inhibit further milk synthesis. Ayadi et al. (2003) demonstrated in a feedlot situation that cisternal volumes can be measured non-invasively using ultrasound technology. Dairy systems based on pasture, such as those in New Zealand, exhibit different challenges to the production of useful data using this technology compared to feed lot systems and the confounding effect of the variability in milking order and the subsequent variations of the intervals between subsequent milking (Molenaar et al. 2012).

}, issn = {1176-5283}, author = {Molenaar A and Leath SR and Caja G and Henderson HV and Cameron C and Challies M and Taukiri K and Chikazhe T and Kaumoana S and Lannou B and Dorleac A and Guy A and Gavin C and Singh K} } @conference {89268, title = {The effect of re-milking following extended non-milking periods on the proliferation and apoptosis of mammary gland epithelial cells in dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {51-53}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

In dairy cows, the increase in milk yield from parturition to peak lactation is attributed to an increase in the secretory activity of mammary epithelial cells (MECs) (Capuco et al. 2001). However, following peak lactation, there is a decline in milk production, which is attributed to the loss of MECs by programmed cell death or apoptosis (Capuco et al. 2001). The role of involution and the factors that regulate it in the bovine mammary gland are not well understood. Previous studies have characterised the process of involution in the bovine mammary gland by determining whether involution is reversible following an extended milk stasis. Involution was fully reversible following seven days of non-milking (Dalley \& Davis 2006), but was only partially reversible following longer non-milking intervals (Noble \& Hurley 1999; Singh et al. 2012).

}, issn = {1176-5283}, author = {Mallah GS and Dobson J and Moon S and Henderson HV and Molenaar A and Guan J and Singh K} } @conference {89264, title = {Genome wide DNA methylation patterns and transcription analysis in sheep muscle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {37-40}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

The Carwell phenotype is a desirable inherited muscular hypertrophy of the Longissimus dorsimuscle in Poll Dorset sheep that does not have any detrimental effect on eating quality, fat deposition or detectable meat tenderness. The Carwell haplotype has been localized to a 350kb region on the distal end of OAR18 near the Callipyge locus (Nicoll et al. 1998) containing three known genes. However, in spite of considerable effort in sequencing and resequencing, the causative mutation has not been identified. Although unsuccessful in identifying the causative mutation, these studies have revealed that the Carwell phenotype displays an imprinted inheritance pattern, with increased muscling associated with inheritance from the sire but not the dam.

}, issn = {1176-5283}, author = {Couldrey C and Brauning R and MacLean PH and Henderson HV and McEwan JC} } @conference {89226, title = {High hydrostatic pressure treatment increases cryo-tolerance of in vitro produced bovine embryos}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {83-85}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Cryo-preservation is a critical tool to manage the logistics of implementing assisted reproductive technologies in practice, which depend upon the availability of synchronised recipient cows for embryo transfer. However, the various cryo-preservation methodologies are noted for compromising the integrity of cells within the embryo, hence reducing subsequent viability. The challenge faced by practitioners in this field isto increase the success rate of producing offspring following embryo cryopreservation.

}, issn = {1176-5283}, author = {Popovic L and Berg DK and Pribensky C and Henderson HV and Wells DN} } @conference {89239, title = {Relative performance of three strains of fine-woolled Merino sheep farmed on Waikato hill country}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {136-142}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Flocks of Saxon (ex Tokanui Research Station), Merryville (ex Tara Hills Research Station) and Fine Peppin (ex Tokanui Research Station) Merino sheep were established at the Whatawhata Research Centre to investigate their relative productivity under North Island hill country conditions. Production data were collected for five years. The Fine Peppin ewes had a higher reproductive rate (0.1 {\textpm} 0.05 (standard error of difference) lambs weaned/ewe joined) with a higher lamb birth weight (0.37 {\textpm} 0.08 kg), lamb weaning weight (1.9 {\textpm} 0.4 kg) and yearling weight (3.5 {\textpm} 0.6 kg), a higher ewe greasy fleece weight (1.2 {\textpm} 0.1 kg) that was longer (7 {\textpm} 2 mm) and coarser (3.0 {\textpm} 0.2 μm) with a greater coefficient of variation of fibre diameter (2.2 {\textpm} 0.4 \%), lower brightness (-1.3 {\textpm} 0.4 CIE Y units) and more yellow (1.1 {\textpm} 0.2 CIE (Y-Z) units) than the Saxon. The Merryville was intermediate between the other two strains for most characteristics. The yearling fleece of each strain exhibited similar trends to the adult fleece. On the basis of the measured performance, and applying wool and lamb price trends between 2007/08 and 2011/12, the differential returns per ewe of the Fine Peppin would be expected to exceed that of the Saxon by $8.80 with the Merryville being intermediate.

}, issn = {1176-5283}, author = {Sumner RMW and Henderson HV} } @conference {78989, title = {The effect of re-milking following extended non-milking periods on lactation in dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {70-72}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {In dairy cows, the cessation of milk removal for extended periods, such as drying-off, initiates the process of mammary gland involution. This results in a decline of mammary secretion and changes in secretion composition. Morphological changes in the mammary gland occur within the first week of non-milking, with extensive re-modelling by the third or fourth week. However, many alveolar structures are retained (Hurley 1989). Thus, involution may be reversible following extended non-milking periods (Noble \& Hurley 1999). Milk yield is fully restored ... continued}, issn = {1176-5283}, author = {Singh K and Swanson K and Henderson HV and Stelwagen K} } @conference {78980, title = {Relative performance of Wiltshire and Perendale sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {28-34}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

Performance data are reported for flocks of Wiltshire and Perendale sheep grazed together for four years on a North Island hill country property (Whatawhata) and for four years on a South Island breeding/finishing property (Winchmore). Wiltshire ewes were lighter than Perendale ewes post-joining at Whatawhata, and at weaning at Winchmore. Greasy fleece weights of the Wiltshire and Perendale yearlings were 0.8 and 2.2 kg respectively, and 0.5 and 3.3 kg respectively for the ewes. As a result of a confounding effect of fibre shedding between day length and date of shearing, Wiltshire ewes exhibited a linear decrease in harvested fleece weight from the yearling stage whereas Perendale ewes showed a curvilinear age effect, with a maximum fleece weight at three to four years of age. Wiltshire ewes had a significantly lower reproductive rate, and lamb survival than Perendale ewes at both locations, with reproductive rate, fertility and litter size increasing significantly following the transfer of the flocks from Whatawhata to Winchmore. While there was no significant difference in the total weight of lambs weaned by the two breeds at each location, the loss in wool production would be compensated by lower shearing and management costs for Wiltshire sheep that shed completely.

}, issn = {1176-5283}, author = {Sumner RMW and Scobie DR and O{\textquoteright}Connell D and Henderson HV} } @conference {79016, title = {The use of milking intervals of individual cows in assessing herd test milk production data}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {186-188}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

Herd testing is a significant expense for dairy farmers but it gives important information about individual cow yields and contributes to the genetic worth status of the cows. While every effort is made to maximise the value of the tests to the farmer there are still opportunities to increase this value further. Estimations of milk yield from herd tests, whether from one or two milkings, rely on the generally held assumption that animals come in to the parlour in a similar order at each milking (DairyNZ 2011) and so the values obtained reflect a nominal 24 hour yield. ... continued

}, issn = {1176-5283}, author = {Molenaar AJ and Henderson HV and ML Burgess and Burgess WG and Johnson DL and Singh K} } @conference {75890, title = {BRIEF COMMUNICATION: Phenotypic selection of cows for lactation persistency}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {136-138}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Lactational persistency is the degree to which early lactation yield persists during the lactation season. Though this is a desired dairy performance trait, it has not been directly selected for in New Zealand dairy populations. In spring-calving pasture-fed cows, peak lactation is reached soon after calving and then declines by about 10\% per month (Davis et al., 2000) until the cows are... Continued}, issn = {1176-5283}, author = {Hickey SM and Singh K and Morris CA and Henderson HV and Molenaar AJ} } @conference {75917, title = {Is there an association between dam live weight and litter structure in a flock of grazing Perendale sheep?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {257-262}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Observational data from a grazing Perendale flock collected between 1985 and 2002 were analysed to investigate whether there was any association between variation in pasture availability over the summer, as reflected in live weight at joining and/or liveweight change between weaning and the subsequent joining, in association with litters of different sizes and sex structure, and the sex ratio of lambs born during the following spring, under pastoral farming conditions. The flock was managed at Whatawhata Research Centre until 1997 and thereafter at Winchmore Research Station. Data for a total of 3,516 lambs were analysed. Between year variation and variation associated with all the assessed factors, was consistent with chance variation. The proportion of males born was not significantly different from 0.50. Ewe age was significant at Winchmore when adjusted for lambing year, and litter size in both the previous and current lambings and liveweight change of the dam between weaning and joining, with more males born to mature ewes. Three percent more male than female lambs died between birth and weaning at both locations. It is unlikely sheep farmers can consistently influence the sex ratio of their lamb crop through changes in their flock management procedures.}, issn = {1176-5283}, author = {Sumner RMW and Henderson HV and Sheppard AM} } @conference {75886, title = {An update on genetic parameters for facial eczema susceptibility in New Zealand dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {117-121}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Resistance/tolerance to facial eczema (FE) is a heritable trait in New Zealand dairy cattle, as measured by genetic variation in liver enzyme levels. AgResearch has been collecting data from herds clinically affected by FE, by blood-sampling all cows in these herds, as a low cost method of phenotyping large numbers of animals. Over the past seven autumns, 66 herds and 14,799 cows were sampled. Breeding values for FE resistance were calculated for 238 sires. One complicating factor was the level of FE-protection provided by zinc sulphate administered through the farm water supply. Variable levels of serum zinc in cows were found, due to factors including water intakes and weather conditions. In zinc-treated herds there were three classes of cows: those still affected by FE, and others seemingly FE-tolerant either through genetics or having enough circulating zinc to provide protection. The zinc status of each herd was recorded at the time of blood sampling after a clinical outbreak. Data were analysed within zinc-treated and not zinc-treated herds to provide genetic parameters for each. Heritabilities in herds according to zinc status were very similar, regardless of zinc status.}, issn = {1176-5283}, author = {Cullen NG and Morris CA and Hickey SM and Henderson HV} } @conference {41784, title = {Gene expression profiling of wool follicle growth cycles by cDNA microarray}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {39-42}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Wool growth in Wiltshire sheep was synchronised by daylength manipulation to allow identification of genes that are regulated during transitions in the wool follicle cycle. Pair-wise comparisons between growing and resting phases were conducted using both direct and indirect cDNA microarray analysis. The two approaches were well correlated at three different levels: overall similar patterns of gene expression, detection of changes in keratin gene expression, and reduced differential expression between closer cycle stages. Using more slides, the indirect approach identified more expressed sequence tags (ESTs) (indirect 1132, direct 444), and had higher coverage of wool keratins (indirect 78\%, direct 42\%). This study demonstrates the usefulness of cDNA microarray for expression profiling in whole skin. Further characterisation of genes identified by this work, particularly the smaller sets of ESTs derived from comparisons at early stages of follicle regression and regrowth, would improve our understanding and provide leads for alternative wool harvesting technology or enhancing wool growth. }, issn = {1176-5283}, author = {Yu Z-D and Gordon SW and Pearson AJ and Henderson HV and Craven AJ and Nixon AJ} } @conference {42057, title = {Testing for quantitative trait loci for lactation persistency in dairy cattle}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {107-110}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Lactational persistency has not been selected for in New Zealand dairy populations. Existing milk production data and pedigrees from New Zealand Holstein-Friesian cattle at pasture, recorded in the Livestock Improvement Corporation database were utilized with a grand-daughter design, for a genome-wide search for a quantitative trait locus for persistency of lactation. Persistency was defined as a weighted sum of test-day yields. A significant region was identified in one grandsire family on Chromosome 3 at microsatellite marker position AGLA247 (chromosomal position 67cM; P <0.05). To verify this result, data from a research dairy herd defining persistency as the mean of three weekly tests of daily yield in March (late lactation) divided by the equivalent daily yields in October (early lactation)) for three seasons beginning in 1997/98 were used in a phenotypic association study on Chromosome 3 only. One allele of marker HUJ246, close to the original region appeared to show an additive effect. The maximal difference between this genotype and the others at this marker locus was 12.3 {\textpm} 4.4\% of the mean persistency. The potential use of this marker in the New Zealand dairy cattle population depends on the current allele frequencies in the industry. }, issn = {1176-5283}, author = {Morris CA and Spelman RJ and Henderson HV and Cullen NG and Hyndman DL and Miller FM and Johnson DL and Molenaar AJ and Grigor MR and Davis SR} } @conference {41783, title = {Use of cDNA microarrays to investigate gene regulation in mastitis as a result of Escherichia coli infection in the bovine mammary gland}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {68}, year = {2008}, month = {Jan}, pages = {37-38}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Brisbane, Australia}, abstract = {Bovine mastitis is the result of an inflammatory event in the mammary gland usually caused by a variety of bacteria in the udder and is one of the three major causes of disease in the Dairy industry world wide. The cost of mastitis in New Zealand is estimated at NZ$180 million for the industry and (DairyInsight, 2006).}, issn = {1176-5283}, author = {van Loenen-den-Breems NY and Molenaar AJ and Henderson HV and Seyfert H-M} } @conference {41894, title = {Effect on fleece weight of combining genes from four flocks independently selected for increased fleece weight}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {195-199}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {This study investigated whether heterosis was present when crossing sheep from four closed Romney flocks selected for increased fleece weight. Three of the flocks had been developed by AgResearch (C, W and H) and one by Massey University (M). Each ewe was joined with a single ram according to a diallel design to generate single-line, two-line and four-line cross progeny. The trial ran from 1988 to 1996 with 599 records available for analysis. In rank order, the mean ({\textpm} standard error of mean) greasy yearling fleece weight (kg), adjusted for year, sex, pre-shearing live weight and days of wool growth was W (3.41 {\textpm} 0.08), H (3.39 {\textpm} 0.12), C (3.31 {\textpm} 0.10), M (3.10 {\textpm} 0.15) for the "single-line" groups, WC (3.40 {\textpm} 0.09), MW (3.36 {\textpm} 0.10), CH (3.24 {\textpm} 0.08), WH (3.16 {\textpm} 0.11), MH (3.14 {\textpm} 0.11), MC (3.14 {\textpm} 0.10) for the "two-line" crosses and 3.26 {\textpm} 0.06 for the four-line cross. Combining sheep from two or more flocks independently selected for increased fleece weight resulted, on average, in no heterosis in wool production among resultant progeny. }, issn = {1176-5283}, author = {Sumner RMW and Clarke JN and Blair HT and Cullen NG and Henderson HV} } @conference {41629, title = {Micro-arrays as a discovery tool for wool genomics}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {66}, year = {2006}, month = {Jan}, pages = {129-133}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Napier}, abstract = {Wool follicle development and growth is a highly ordered and complex process involving the sequential expression of numerous genes within diverse cell populations. The aim of present studies using microarray analysis is to identify genes and pathways involved in the growth of wool follicles which could be utilised to increase farm productivity and improve the characteristics of Australasian wools. An ovine cDNA array was developed including sequences derived from sheep skin containing wool follicles in different growth stages encompassing many structural and regulatory genes necessary for follicular growth. Initial comparison of stages of wool follicle regression show marked changes in the expression levels of numerous genes including wool keratins. Two parallel research projects in Australia and New Zealand supported by SheepGenomics are currently utilising microarray technology to profile gene expression during key stages of wool follicle development in the foetus and follicular cycling associated with fleece shedding. }, issn = {1176-5283}, author = {Yu Z-D and Bawden CS and Henderson HV and Nixon AJ and Gordon SW and Pearson AJ} } @conference {41460, title = {The use of microarrays to investigate gene regulation in the bovine mammary gland during Streptococcus uberis mastitis}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {64}, year = {2004}, month = {Jan}, pages = {14-16}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {Bovine mastitis is one of the most costly dairy-based diseases worldwide with an estimated $60 M loss to New Zealand per season. Mastitis infections are a result of bacterial or fungal pathogens becoming established in the udder, and are detected by the increase of somatic cells in the mammary gland, bacteriology data and physical signs of infection. In New Zealand, mastitis is usually a result of a gram-positive bacterial infection (Brookbanks, 1966). Of these bacteria, Streptococcus uberis is emerging as one of the most prevalent causative organism of mastitis in New Zealand (McDougall, 2002). It resides naturally in the environment making prevention of the disease difficult. Currently the main means of controlling the disease is through administering antibiotics following identification of infection. The mammary gland is protected from invasion by the activation of non-specific (innate) and specific defence mechanisms. The innate immune response is the predominant defence during the early stages of infection and is induced rapidly at the site of infection (Sordillo et al., 1997). Although the local mammary innate immune response has been widely investigated, studies have focussed on known antibacterial compounds and little is known about the novel compounds in bovine milk and how these contribute to the defence system of the mammary gland. The mechanism by which the mammary gland innate immune system is active against S. uberis is poorly understood. By developing an understanding into the way S. uberis induces an immune response in the mammary gland and the effect of infection on mammary gland metabolism we may identify components which can be utilised to either reduce the symptoms of/or prevent or cure S. uberis mastitis. }, issn = {1176-5283}, author = {Swanson KM and Henderson HV and Farr VC and Davis SR and Oden K and Stelwagen K and Molenaar A and Singh K and Prosser CG} } @conference {40986, title = {The value of monozygotic twins in milk composition experiments.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {58}, year = {1998}, month = {Jan}, pages = {55}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Monozygotic (identical) twins have for many years been used to increase the statistical power of experiments in a range of scientific disciplines (Dick and Whittle,1951). In dairy cows, variation within identical twinsets for a given biological parameter is usually substantially less than the variation between unrelated cows or between fraternal twinsets (Hancock 1953; Brumby and Hancock, 1956). Thus the number of identical twins required in an experiment is often considerably less than the number of unrelated cows necessary to achieve the same statistical precision. The experiments described here were conducted to quantify the twin efficiency values of a range of milk composition parameters.}, issn = {1176-5283}, author = {Auldist MJ and Mackle TR and Hooper RJ and Henderson HV} } @conference {40265, title = {Effects of varying the progesterone content of CIDR intravaginal devices and multiple CIDR treatments on plasma hormone concentrations and residual hormone content}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {471-472}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {No abstract supplied }, issn = {1176-5283}, author = {Macmillan KL and Washburn SP and Henderson HV and Petch SF} } @conference {40223, title = {Facial eczema in Jersey cattle: heritability and correlation with production}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {255-260}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Fifty-eight possums (28 male, 30 female) were captured from the wild. Animals were grouped into ages of 1, 2-4 and 5+ years. Males were always heavier than females of the same age, while carcass weight increased significantly with age up to 5+ years. Age had a more pronounced effect on carcass composition and meat quality than sex. At all ages, and in both sexes, possums produced carcasses which were high in dissected lean (78-80\%) and low in fat (0.8-2.6\%). Their meat was very high in protein (24-26\%) and low in fat (1.4-2.0\%). Tenderometer results showed that all age groups produced meat which would be rated as acceptably tender. }, issn = {1176-5283}, author = {Morris CA and Towers NR and Tempero HJ and Cox NR and Henderson HV} } @conference {40055, title = {Some effects of injecting a prostaglandin F2 alpha (Lutalyse) during the post-partum period on the subsequent fertility of dairy cows}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {65-68}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The need to determine the scientific base and cost-effectiveness of traditional inspection methods is particularly important in New Zealand, a major exporter of sheep meat. Risk assessment as applied to potential human health hazards in a broad sphere can also be adapted to risk associated with a meat inspection programme. Risk associated with an export inspection programme aimed at maintaining market access must include human health, animal health and aesthetic defects. A quantitative risk assessment model is described for 2 different inspection methods for liver fluke (Fasciola hepatica) in adult sheep. Unless sensitivity and specificity data are produced, quantitative risk assessments are statistically invalid. Determination of specificity also allows cost-benefit analyses to be correctly performed.}, issn = {1176-5283}, author = {Macmillan KL and Day AM and Taufa VK and Henderson HV and Allison PA} } @conference {40053, title = {Trends in monthly milkfat production of cows in seasonal dairy herds in New Zealand}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {57-59}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Changes in shape of the femur and the m. semitendinosus occurring with developmental growth are described. It is shown that three-quarters of growth in muscle volume is consequent upon growth in length of bone, while shape changes in muscle account for only one quarter of growth in muscle volume. Attention to the role of bone is necessary in studies of muscle protein synthesis and muscle growth.}, issn = {1176-5283}, author = {Macmillan KL and Henderson HV} } @conference {39886, title = {Variations in milkfat test, liveweight, colour and height associated with the use of Friesian sires in some New Zealand dairy herds}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {44}, year = {1984}, month = {Jan}, pages = {71-74}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Sixteen high (HS) and 16 low (LS) bloat susceptible dairy cows were offered hay or pasture when not lactating and pasture or 75\% pasture 25\% hay when lactating. There were no significant differences between susceptibility groups in voluntary intake or apparent digestibility of DM, OM, nitrogen or energy on either occasion. There was a trend for HS cows to produce less milk of higher fat, protein and lactose content than LS cows. Rumen digesta studies on 5 HS and 5 LS rumen-fistulated, dry, pregnant cows at a maintenance level of feeding indicated that the proportion of digesta lost from the rumen after feeding was higher for LS cows than HS cows on pasture, but not on hay. There was no significant difference between susceptibilities in post-feeding fluid dilution rate. HS cows tended to have higher rumen fluid osmolality and Na concentration during the post-feeding period on pasture, but not on hay.}, issn = {1176-5283}, author = {Macmillan KL and Henderson HV and Bryant AM} } @conference {39747, title = {Breeding for facial eczema resistance - A progress report}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {41}, year = {1981}, month = {Jan}, pages = {273-278}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, issn = {1176-5283}, author = {Campbell AG and Meyer HH and Henderson HV and Wesselink C} }