@conference {3672, title = {Contract session: Application of genetic technologies to the New Zealand sheep industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {184-187}, address = {Dunedin}, abstract = { }, issn = {1176-5283}, author = {Jopson NB and Linscott EM and Young MJ and Dodds KG and Clarke SM and Rowe SJ and Byrne TJ and Alder GF} } @conference {79009, title = {A comparative analysis of genetic trends within the New Zealand sheep industry}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {159-162}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Rates of genetic progress made by Dual Purpose and Terminal Sire flocks in the New Zealand sheep industry between 1990 and 2007 have previously been examined (Amer 2009) and showed substantial gains in the rate of progress since the introduction of Sheep Improvement Ltd. (SIL) and SIL-ACE (Advanced Central Evaluation). Key findings from this earlier study showed that the rates of genetic progress doubled following the introduction of SIL, and increased by a further 50\% after the introduction of the Beef + Lamb New Zealand Central Progeny test (CPT), which effectively evaluates the performance of key industry sires, providing the ... continued}, issn = {1176-5283}, author = {Sise JA and Byrne TJ and Jopson NB and Young MJ and Amer PR} } @conference {60964, title = {SIL - progress over a decade}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {148-152}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {In the 10 years that Sheep Improvement Ltd (SIL) has been operational, the system has continued to develop to meet the needs of breeding flock owners and their ram buying clients. New traits have been added to the evaluation. More flocks are using across-flock evaluations, but there is the opportunity to grow this significantly. The language of SIL is well accepted by industry and offers the most likely path to integration of DNA based genetics into the sheep industry. While a large proportion of rams used by the New Zealand sheep industry come from SIL flocks, a significant section of the industry are still not comfortable with SIL figures when purchasing rams. Greater penetration into the ram buying industry and further into the meat processing industry are challenges for SIL and its collaborators. SIL must maintain and enhance its relevance to industry. This means focused research that addresses key issues and a significant extension effort to increase the proportion of industry that has confidence in using SIL and related technologies. }, issn = {1176-5283}, author = {Young MJ and Wakelin R} } @conference {60965, title = {SIL-ACE - Increasing access to genetic information for sheep farmers}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {153-154}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {SIL-ACE is a large-scale, across-flock, across-breed genetic evaluation carried out bi-monthly by SIL. Goal trait groups considered include Growth, Meat (carcass merit), Wool, Reproduction and Resistance to internal parasites. The SIL-ACE dataset comprises over 330 flocks and 3.2 million animals. Leader lists for top-rated 200 sires are published on the www.sil.co.nz website. These comprise the top 5 to 10\% of sires for each index or goal trait group considered. Visual depictions of flock connectedness are also provided. Breeders obtaining within flock reports based on the SIL-ACE genetic evaluation, can use a percentile bands table as a scale to judge the merit of animals they are considering for selection. Developments underway will lead to other traits being added to the SIL-ACE evaluation such as lamb survival and ewe performance, resulting in more powerful selection tools to better target genetics suited to a particular users needs. }, issn = {1176-5283}, author = {Young MJ and Newman S-AN} } @conference {60967, title = {Trans-Tasman genetic evaluation of sheep - spreading the net wider}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {158-160}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {At the instigation of local breed groups, Sheep Improvement Ltd. (SIL) and Sheep Genetics (SG) exchanged flock data and conducted genetic evaluations on the combined dataset. Results from each system show only modest changes in breeding values compared to analyses of their respective within country datasets. Correlations of breeding values (BVs) were 96 to 100\% for weaning weight, autumn live weight, ultrasonic muscle, ultrasonic fat, fleece weight and number of lambs born. Correlations between BVs generated by the two systems from the same datasets were less strong but still good at 69 to 89\%, for most traits. This was attributed to differences in parameters used by the two analysis systems and to some measurements being taken at different ages. The weakest correlations occurred for ultrasound scan traits at 14 to 65\% since SG adjusts these to constant {\textquoteright}carcass{\textquoteright} weight but SIL does not. It is concluded that the best option for breeders seeking superior genetics internationally is to facilitate data exchange and have analysis and reporting done within their own country. }, issn = {1176-5283}, author = {Young MJ and Newman S-AN and Apps R and Brown DJ} } @conference {40816, title = {Prediction of carcass tissue weight in vivo using live weight, ultrasound or X-ray CT measurements}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {205-211}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Twenty-one Dorset Down ewe hoggets (49.4kg body weight, 9months old) were scanned by ultrasound and X-ray computer tomography (CT). Total carcass tissue (fat, muscle and bone) weights were assessed by the Cavalieri procedure from 16-18 CT slices per animal. Additional CT slices were taken at four anatomical reference sites; 7th thoracic (TV7), 2nd lumbar and 5th lumbar vertebrae (LV5), and mid-shaft of the femur. Subcutaneous fat depth and muscle depth were assessed over the last rib using ultrasound. Body weight, ultrasound measurements and reference slice carcass tissue areas were used to predict total carcass tissue weights by multiple regression techniques. In combination with BW, single CT slices predicted tissue weight more accurately than ultrasound measurements with BW for fat (R2=72-84\% vs. 63\%) but not for muscle (R2=79-87\% vs. 83\%) or bone (R2=62-66\% vs. 65\%). The best combination of two CT slices was TV7 \& LV5. In combination with BW these improved prediction accuracy further (fat, R2=92\%, muscle, R2=91\%, bone, R2=71\%). It is possible that data from a single CT slice predict carcass tissue weight less accurately than expected due to anatomical registration errors despite CT producing better quality images than ultrasound. These errors are attributed to scanning protocol constraints for CT equipment. Two or more CT slices need to be scanned in order to predict tissue weight more accurately than ultrasound.}, issn = {1176-5283}, author = {Young MJ and Nsoso SJ and Logan CM and Beatson PR} } @conference {40598, title = {Carcass, liver and kidney characteristics of lambs grazing plantain (Plantago lanceolata), chicory (Cichorium intybus), white clover}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {197-200}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Plaintain (Plantago lanceolata L.) is being evaluated in New Zealand as a potential pasture species because of its supposed medicinal attributes. Seventy six, four month old Coopworth ram lambs were rotationally grazed on either plantain (PL), chicory (Cichorium intybus L.; CH), white clover (Trifolium repens L.; WC) or perennial ryegrass (Lolium perenne L.; RG) for 82 days from January to April, 1993 at an allowance averaging 1.8 kg green DM/lamb/day. At slaughter treatment differences in carcass weight were apparent (16.8, 18.3, 20.1 and 15.6kg, respectively, for PL, CH, WC and RG). After adjustment for body size no differences in carcass characteristics were apparent between treatments. However, differences still existed for liver and kidney size. WC lambs were the heaviest at slaughter and had the largest livers after adjustment. In contrast, kidney size did not follow liveweight with PL lambs having the largest kidneys after adjustment. Serum urea and creatinine levels indicate that renal function was not impaired in PL lambs relative to RG lambs. }, issn = {1176-5283}, author = {Deaker JM and Young MJ and Fraser TJ and Rowarth JS} } @conference {40611, title = {Genetic and phenotypic parameters associated with lean tissue growth in Dorset Down sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {251-254}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Genetic and phenotypic parameter estimates were derived from performance data collected over nine years for the Lincoln University Dorset Down flock. Data were for animals born each spring and run at pasture. Ewes (n=922) were measured in autumn and rams (n=819) in winter. Measurements were live weight and in vivo fat and muscle depths. Genetic and phenotypic parameters were estimated using multi-variate AIREML analyses by fitting an individual animal model with animal as a random effect, birth rank, age of dam and year of birth as fixed effects and age at measurement as a covariate. Multi-variate heritability estimates ({\textpm} s.e.) for live weight, fat and muscle depths were 0.42 ({\textpm}0.04), and 0.30({\textpm}0.05) for rams and 0.26({\textpm}0.01), 0.20({\textpm}0.05) and 0.13({\textpm}0.03) for ewes respectively. Estimates of genetic correlations were generally moderate to high for the two sexes. The genetic correlation between live weight and fat depth was significantly different for the two sexes, with rams (0.42{\textpm}0.10) having a higher value than ewes (0.24{\textpm}0.02). Phenotypic correlations differed between the sexes, with estimates for ewes being slightly higher. For both sexes, parameter estimates were different from those used to derive the indices used to select for lean tissue growth, ram estimates being consistently higher while those for ewes were more equivocal. }, issn = {1176-5283}, author = {Nsoso SJ and Young MJ and Beatson PR and Bell ST} } @conference {40597, title = {Reduction of carcass fatness in overfat lambs fed low energy diets supplemented with protein}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {193-196}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Forty crossbred (Dorset Down x (Border Leicester x Romney)) overfat (ultrasonic GR 13.3 {\textpm} 0.5 mm), ewe lambs aged approximately 6 months and weighing 40.4 ({\textpm}0.8) kg live weight were randomly allocated to either an initial slaughter group or one of three dietary treatment groups on the basis of live weight and ultrasonic GR measurement. Dietary treatments consisted of three pelleted diets that contained 101 g (MP), 189g (HP) and 274g (SP) crude protein with estimated metabolizable energy contents ranging from 7.1 to 7.8 MJ per kg dry matter. Lambs were fed ad libitum for 42 days. Throughout the experiment, daily live weight gain was significantly higher for MP than HP or SP lambs (P<0.01). However, this was solely due to greater gut fill for MP lambs compared to HP and SP lambs (P<0.05). There were no significant treatment effects on mean carcass weight. However, all treatments significantly (P<0.05) reduced GR tissue depth (measured on hot carcass at slaughter) by 20\%, 19\% and 24\% for MP, HP and SP lambs, respectively. Chemical fat content in the carcass significantly decreased (8\%, 12\% and 16\%, respectively (P<0.05)). Differences between dietary treatments were not significant for these traits. M. longissimus dorsi area and protein content of the carcass were not significantly altered by dietary treatments (P>0.05). It is concluded that carcass fat in overfat lambs can be successfully reduced by feeding diets low in energy and supplemented with medium to high levels of protein without adverse effects on carcass protein. High levels of dietary protein do not appear to be necessary for this to occur. }, issn = {1176-5283}, author = {Liu AH and Young MJ} } @conference {40612, title = {Responses to selection for lean tissue growth in Dorset Down sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {255-260}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Responses to selection using a lean tissue growth index were estimated from performance data of the Lincoln University Dorset Down flock. Data were available for ewes (n=922) born in the years 1984 - 1991 and rams (n=816) born in 1984 - 1992. Data were from two closed lines, one control and the other selected for high lean tissue growth. Initially selection was on the basis of an index comprising measurements of live weight and fat depth. Subsequently muscle depth was incorporated into the index. Ewes and rams born in spring each year were run separately at pasture from weaning (late summer) onwards. Performance testing was in the following autumn for ewes and winter for rams. Measurements were live weight and in vivo ultrasonic fat and muscle depths. Responses were calculated from regression of the difference between the line means for breeding value against time. Breeding value estimates were derived by AIREML analyses. Both sexes exhibited desirable responses in all component traits: rams; +0.290kg/yr, +0.019mm/yr and -0.013mm/yr and ewes; +0.154kg/yr, +0.028mm/yr and -0.028mm/yr for live weight, muscle and fat depths respectively. Increases in muscle depth occurred after it was incorporated into the selection index. }, issn = {1176-5283}, author = {Nsoso SJ and Beatson PR and Young MJ and Logan CM} } @conference {40602, title = {Ultrasound measurements predict estimated adipose and muscle weights better than carcass measurements.}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {215-218}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Seventy-six 6 month old Coopworth ram lambs were scanned with ultrasound for muscle depth B, fat depth C and tissue depth GR. Lambs were slaughtered, then B, C and GR measured directly on each carcass. The hindquarters (loin and hind legs) of each carcass were boned out and soft tissue minced then analysed for lipid and protein content. From these, hindquarter adipose and muscle weights were estimated. Correlations of estimated tissue weights with ultrasound measurements were consistently higher than those with direct measurements (averaging 0.423 versus 0.293, respectively). The latter method may be more prone to measurement errors associated with displacement, damage or distortion of tissue or positioning of the measurement site. It is concluded that ultrasound measurements may be better than those made directly on the carcass for predicting tissue weights. }, issn = {1176-5283}, author = {Young MJ and Deaker JM} } @conference {40371, title = {Factors affecting repeatability of tissue depth determination by real-time ultrasound in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {37-40}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {The behaviour of 7476 calves transported on double- or triple- decker trucks was studied during unloading. Recorded behaviour was classified into 2 categories (upright or not upright) and the frequencies of these at three ramp slopes (4.2, 12 and 18.8 ) are presented. The proportions of animals upright on the 3 slopes (low, medium and high) were 93, 74 and 20\%. On average, 100 calves were unloaded in 5.3, 7.7 and 7.1 min down the low, medium and high slopes, respectively. Improvements in welfare of bobby calves and probably reduced bruising would result if ramp slopes were kept at less than about 12 so that most animals could remain upright. }, issn = {1176-5283}, author = {Young MJ and Deaker JM and Logan CM} } @conference {40373, title = {Subcutaneous fat distribution as assessed by ultrasound in Border Leicester and Dorset Down ewe hoggets}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {52}, year = {1992}, month = {Jan}, pages = {45-48}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A study of growth and venison production from weaner red deer grazing pure "Pawera" tetraploid red clover (RC) or conventional perennial ryegrass/white clover (PRG) pasture was conducted, with the objective of attaining a minimum slaughter liveweight (92 kg; 50 kg carcass) by 12 months of age in the stags. Ten weaner red deer stags and 10 weaner red deer hinds were rotationally grazed on either RC or PRG pasture. In autumn and spring, forage allowances were respectively, 7 kgDM/h/d and 8 kgDM/h/d. In winter, the animals from both groups were grazed together on PRG pasture, at a residual dry matter of 1100 kg/DM/ha; 0.5 kgDM/h/d of meadow hay was also provided. Liveweight gains of RC and PRG stags were respectively 263 vs 192 g/d, 101 vs 106 g/d and 362 vs 341 g/d during autumn, winter and spring. With hinds, the liveweight gains of RC and PRG groups were respectively 198 vs 173 g/d, 52 vs 53 g/d and 242 vs 218 g/d during autumn, winter and spring. Animals grazing RC pasture had significantly higher liveweight gain during autumn (p<0.01), but not in winter and spring. At one year of age, stags grazing RC were 7 kg heavier and hinds 3 kg heavier than animals grazing PRG pasture. Animals grazing RC pasture had higher voluntary feed intake (VFI) in both autumn (p<0.10) and spring (p<0.001), than animals grazing PRG pasture. All stags grazing RC pasture reached the minimum slaughter liveweight by one year of age, compared to 75\% grazing PRG pasture. Stags that had grazed RC produced heavier carcass weights (59.9 vs 54.5 kg, p<0.01), and had higher carcass dressing percentage (55.3 vs 53.2\%, p<0.01). RC has potential as a special purpose forage for the growth of weaner red deer. }, issn = {1176-5283}, author = {Deaker JM and Young MJ} } @conference {40248, title = {Genetic parameters for in vivo body measurements in Suffolk sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {50}, year = {1990}, month = {Jan}, pages = {403-406}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Attention is drawn to developments in the public perception of animal farming which have the potential to adversely affect the animal industry in the future. These developments, which are occurring around the world, stem from review of ethical aspects of animal farming and from concern at the ecological impact of animal farming. Of particular concern is the emission of greenhouse gases - especially methane - by ruminants. This paper discusses measures by which these emissions could be reduced, and how national policy decisions regarding greenhouse gas emissions on farms may be reached. Opportunities for this Society are pointed out. }, issn = {1176-5283}, author = {Young MJ and Simm G} } @conference {40111, title = {Short- and long-term effects of intestinal parasitism on growth in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {48}, year = {1988}, month = {Jan}, pages = {157-162}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Skin and fleece samples were taken from 637 ewes of Romney (R), Superfine Merino (SFM), Local Merino (LM), Superfine Merino x Romney (SFMxR), Local Merino x Romney (LMxR) and Backcross (BX) (3/4 SFM) genotypes. Secondary to primary follicle ratio (S/P), total follicle density (n(P+S), primary follicle density (nP), mean fibre diameter (MFD), quality number (QN), staple length (SL); total crimp number (TCN); live weight (LWT) and greasy fleece weight (GFW) were evaluated. Differences between the various genotypes, ages, years of sampling and birth/rearing ranks for these follicle and fleece characteristics were analysed. There were between genotype differences in significance of fixed effects. Genotypes having Merino ancestry with much large follicle populations had more significant fixed effects, but year of sampling and birth/rearing rank were seldom significant. Repeatability estimates for follicle and fleece characteristics ranged fr4om 0.44 to 0.89. Total follicle density and primary follicle density were positively correlated but the degree of association was higher between S/P and n(P=S). Both within and across genotypes, the correlations between S/P and MFD were negative. The low correlations between nP and GFW reflect the genotypes studied, nP having less effect on GFW and MFD in breeds with Merino ancestry. Heterosis was estimated in several ways, the means of groups representing the parent breeds being compared with the mean of each generation of the crossbred genotypes. The follicle traits, as well as MFD and QN showed negative heterosis. Live weight and GFW showed positive heterosis in the F1 SFMxR and LMxR groups of 6.84 kg, 5.99 kg and 0.18 kg and 0.47 kg respectively. The crossbreds weighed more and produced heavier fleeces than the purebreds but with no concomitant increase in MFD over the parental breed mean.}, issn = {1176-5283}, author = {Young MJ and Sykes AR} } @conference {40057, title = {Bone growth and muscularity}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {73-75}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Highly prolific flocks of Romney, Coopworth and Perendale sheep have been established from the progeny of ewes screened from industry. Ovulation rates of 1.5-year-old Romney, Coopworth and Perendale ewes were 1.82, 2.08 and 1.87 respectively. Corresponding ovulation rates for older ewes were 2.13, 2.27 and 2.07. Mean litter size of 1.5-year-old Romney, Coopworth and Perendale ewes was 1.63, 1.87 and 1.61 respectively and for older ewes the respective litter size was 1.88, 1.94 and 1.78. The proportion of ewes twinning ranged from 0.57 to 0.69. Within the flocks there are some family lines which are showing outstanding prolificacy and are the subject of a progeny testing programme.}, issn = {1176-5283}, author = {Young MJ and Sykes AR} } @conference {40056, title = {Computer aided tomography - comprehensive body compositional data from live animals}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {47}, year = {1987}, month = {Jan}, pages = {69-71}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {A proposal for the development of a three-stage computer-based system for the acquisition and retrieval of disease and defect data for lambs slaughtered in export premises is described. Stage 1 is an extension of the existing manual ticketing and administrative routine. A slaughter-line computer keyboard would allow continuous collection of data on an individual flock basis, as well as significantly decreasing meat inspector, processor and information servicing workloads. The data base would also provide a statistical base for regulatory decisions and assist the processor{\textquoteright}s quality control programme. Stage 2 is a vertical integration of the inspection service with other agencies involved in the livestock production system. Long-term aims are promotion of producer efficiency and payment by quality. By accumulating both individual and regional flock health profiles, differential cost-effective processing and inspection programmes can be applied. Production and market-related disease and defect data has wide application as a commercial resource. Stage 3 is an integrated meat inspection system with a national disease and residue surveillance centre.}, issn = {1176-5283}, author = {Young MJ and Garden KL and Knopp TC} } @conference {39951, title = {Skeletal changes and some muscle-skeletal relationships during growth and undernutrition in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {45}, year = {1985}, month = {Jan}, pages = {93-96}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Eight Friesian bull calves from high breeding index (HBI) parents (mean BI=134) and 8 from low breeding index (LBI) parents (mean BI=104) were allocated to 1 of 2 levels of milk intake from 3 weeks of age until weaning at 7.5 weeks of age. The calves were then grazed at pasture and weighed at 21 to 25 weeks of age. LM calves consumed more herbage organic matter (OM) both before (P<0.01) and for 3 weeks after (P<0.05) weaning. Increasing daily milk intake by 1 litre decreased daily herbage OM intake by 0.11 kg. The total DE intake from 3 weeks to 10.5 weeks of age did not differ significantly between treatments. HM calves grew faster (P<0.05) than LM calves in the pre-weaning period, but no differences were observed from them on. At no stage were significant differences observed in calf live weights between milk treatment groups. There were significant differences in growth rate or herbage intake between BI groups, nor any significant interactions between BI and levels of milk intake.}, issn = {1176-5283}, author = {Young MJ and Sykes AR} }