@article {3672,
	title = {Genetic parameters for velvet antler of farmed red deer and wapiti},
	journal = {New Zealand Journal of Animal Science and Production},
	volume = {82},
	year = {2022},
	month = {01/2022},
	pages = {77-81},
	address = {Online},
	abstract = {<p>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 \&gt; 50,000 records from 25,087 individuals and 1,419 sires. Mean velvet weights ranged from 2.71 ({\textpm}1.01) at 2-years, to 5.79 ({\textpm}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 {\textpm} 0.03, 0.02 {\textpm} 0.03) and low-moderate respectively (0.24 {\textpm} 0.08, 0.18 {\textpm} 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.</p>
},
	issn = {1176-5283},
	author = {Ward JF and McIntyre SB and Jopson NB and Newman S-AN}
}
@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 {79024,
	title = {Family-based selective breeding of New Zealand Abalone, Haliotis iris: challenges and opportunities},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {72},
	year = {2012},
	month = {Jan},
	pages = {216-221},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {In 2007 the National Institute of Water and Atmospheric Research in New Zealand initiated a family-based selective breeding programme for the New Zealand Abalone, Haliotis iris, with commercial partner OceaNZ Blue Ltd. to investigate the genetics of key performance traits in a cold water and a warm water site and the influence of the early rearing environment on family performance. A total of 101 Abalone families were established using farmed and wild broodstock from multiple locations around New Zealand. Families were reared separately for nine to 14 months prior to tagging at ~15-20 mm shell length and then combined. Families were also pooled during early rearing, up to seven days post-fertilisation and later genotyped. This allowed estimation of individual tank environment effects on family performance. Length, weight and growth rate have been recorded bi-annually plus evaluation of quality traits such as foot darkness and shell colour at a market size of ~80 mm. Relative family performance has generally been consistent across sites, but is moderately influenced by early environment. The growth traits were found to be highly heritable with high genetic correlations among traits indicating good response to selection for increased growth can be expected.},
	issn = {1176-5283},
	author = {Symonds JE and Moss G and Jopson NB and Roberts R and Birss J and Heath P and Walker SP}
}
@conference {60956,
	title = {Background effects on ewe lambing and weaning performance in well recorded breeding flocks},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {69},
	year = {2009},
	month = {Jun},
	pages = {115-117},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {Results of analyses of Sheep Improvement Ltd. (SIL) data (27 flocks and 128,203 lambings) showed a substantial impact of ewes being scanned pregnant but failing to rear a lamb (wet-dry), on weight of lamb weaned at the next lambing. Compared to ewes that reared a lamb at the previous lambing, {\textquoteright}wet-dry{\textquoteright} ewes had 0.3 to 0.5 less lambs born per ewe lambing, lamb survival rates were lower by 60 to 70 percentage points and weaning weights up to 0.5 kg lighter per lamb weaned. These effects compounded into 30 to 40 kg less weight of lamb weaned per ewe. The failure to rear part of a litter, such as one lamb of a set of twins, had less effect on performance at next lambing and weaning, than loss of the whole litter. Those ewes that previously gave birth to three lambs weaned 4 kg less lamb weight than ewes that previously gave birth to singles, after allowing for their higher genetic drive for prolificacy. A modest but significant effect of previous litter size was observed on weight of lamb weaned within each litter size category. Lamb survival was observed to be 2\% lower (P <0.01) for twin ewes that had failed to rear one of their two lambs, compared with those that had reared both in their previous lambing. },
	issn = {1176-5283},
	author = {Amer PR and Sise JA and Jopson NB and Bray AR}
}
@conference {60968,
	title = {Developments in the sheep meat industry: Genetic evaluation of meat yield},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {69},
	year = {2009},
	month = {Jun},
	pages = {161-164},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {Sheep Improvement Ltd. has a {\textquoteright}MEAT{\textquoteright} Goal Trait Group which is used to select animals on their genetic merit for meat production. Breeding values are calculated for weight of carcass lean, carcass fat and carcass weight. These breeding values are estimated from live weight and ultrasonic eye muscle dimension data, with the option of incorporating computed tomography (CT) measurements. This served the sheep industry well while carcasses were graded on the basis of carcass weight and GR tissue depth. However, deregulation in the meat industry has seen individual meat processors developing carcass grading systems which not only improve estimates of lean and fat, but also estimate retail yield within individual cuts. SIL have developed a {\textquoteright}MEAT YIELD{\textquoteright} module in response to these changes which estimates breeding values for lean weight in the shoulder, loin and hindleg primal cuts. Meat yield data collected from surplus slaughtered progeny are added to live weight and ultrasonic eye muscle data to predict the breeding values. Slaughter progeny should be randomly selected to avoid biasing the meat yield data. This module is likely to be developed further as additional grading systems are implemented, and equations to translate data into standardised measurements will be required. },
	issn = {1176-5283},
	author = {Jopson NB and Newman S-AN and McEwan JC}
}
@conference {60978,
	title = {Genetic and phenotypic parameter estimates for growth, yield and meat quality traits in lamb},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {69},
	year = {2009},
	month = {Jun},
	pages = {210-214},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {The Meat and Wool New Zealand Central Progeny Test has evaluated 143 sires from terminal and dual purpose breeds for meat yield and growth. Meat quality traits, including pH, fat and meat colour (CIE L*, CIE a*, CIE b*) have also been measured. This paper determines genetic variation in these quality traits and their correlations with growth and meat yield. Progeny were drafted for slaughter at a threshold live weight of 34 kg at weaning and 36 kg for subsequent slaughters. Fat colour, eye muscle meat colour and meat pH were measured 24 hours post-slaughter, with meat colour measured after a 30 minute bloom. Heritabilities and genetic correlations between traits were calculated from the measurements. Data were analysed with a linear mixed model in ASReml. Results showed significant variation among sires for meat quality. Heritabilities were moderate for most meat quality traits: fat colour (CIE b* 0.42), initial meat colour (CIE L* 0.29, CIE a* 0.19) and pH (0.12). Relationships between meat quality and yield/growth showed that meat CIE L* had a positive genetic correlation with weaning weight (0.42). Simulated index selection for growth rate and meat yield predicted a small increase in meat lightness and decline in fat yellowness (0.231 and -0.227 units per generation and unit selection intensity, respectively). },
	issn = {1176-5283},
	author = {Payne GM and Campbell AW and Jopson NB and McEwan JC and Logan CM and Muir PD}
}
@conference {60979,
	title = {Genetic parameters for primal cut meat yield traits in sheep},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {69},
	year = {2009},
	month = {Jun},
	pages = {215-219},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {Lamb carcass grading is changing from classification on carcass weight and tissue depth (GR) to yield grading systems such as VIAscan{\textregistered}. Under the VIAscan{\textregistered} system, farmers receive information on the percentage lean meat yield from the hindleg, loin and shoulder primal cuts, and payments are based on these measurements. Genetic improvement programmes for meat have concentrated on producing age-adjusted breeding values for carcass lean and fat weight from live weight and ultrasonic eye muscle measurements. This has worked well for grading using carcass weight and GR, but does not quantify differences in yield between meat cuts. Carcass and VIAscan{\textregistered} yield data collected for the Meat and Wool New Zealand Central Progeny Test were analysed to determine heritabilities and genetic and phenotypic correlations for meat yield traits. The dataset contained around 6,600 progeny from 143 terminal sire or dual purpose rams. Data were analysed using linear mixed models in ASReml. The results showed significant variation between sires for lean yield traits. Heritabilities for age-adjusted lean weight in the hindleg, loin and shoulder were 0.40, 0.37 and 0.42, respectively. Genetic correlations for age-adjusted weight of lean by carcass region were all high (range 0.94 to 0.96), but were lower (0.62 to 0.85) when adjusted to constant carcass weight. },
	issn = {1176-5283},
	author = {Jopson NB and McEwan JC and Logan CM and Muir PD}
}
@conference {42048,
	title = {Artificial insemination success rates for Meat and Wool New Zealand central progeny test sires},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {68},
	year = {2008},
	month = {Jan},
	pages = {77-78},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Brisbane, Australia},
	abstract = {National progeny testing schemes have become important components of national sheep genetic improvement programmes in Australia, France, and New Zealand (Fogarty et al., 2002; Bib{\'e} et al., 2002; Campbell et al., 2005). In 2001 the Alliance Central Progeny Test was established, this was combined in 2005 with the Elite Lamb Progeny Test to become the Meat and Wool New Zealand Central Progeny Test (CPT). Over the past six seasons, a total of 120 leading industry sires, comprising 14 different breeds, have been mated via artificial insemination. CPT rams are genetically connected via common sires ...Continued },
	issn = {1176-5283},
	author = {McLean NJ and Dodds KG and Knowler KJ and Jopson NB and Behrent M and Logan CM and Muir PD and Shackell GH and McEwan JC}
}
@conference {41723,
	title = {Estimation of autumn live weight breeding values in progeny test datasets when progeny are slaughtered to achieve a target carcass weight},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {67},
	year = {2007},
	month = {Jan},
	pages = {175-179},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Wanaka},
	abstract = {An analysis was undertaken to investigate how lamb autumn live weight breeding values could be calculated from fixed carcass weight progeny tests (e.g. lambs slaughtered at monthly intervals at a threshold carcass weight). Analysis of growth rate is problematic for this progeny test design as the slaughter groups may experience vastly different environmental conditions, both within and between years. Variance components were estimated from an animal model using restricted maximum likelihood (REML) on data from 11,411 Coopworth progeny records and 126 Coopworth sires. The dataset contained records of weaning weight and live weight at four, five and six months of age (LW4, LW5 and LW6, respectively) collected from 1995 to 2004 in a flock run at Woodlands Research Station. The multivariate mixed linear model included lamb birth day deviation as a covariate, sex of lamb, birth rearing rank, age of dam and live weight contemporary group as fixed effects, and sire as a random effect. The WWT model also had dam fitted as a random effect to give WWT direct and maternal effects (WWTdand WWTm). The analysis was then repeated, but with animals records removed from the dataset once they achieved a threshold weight of 31 and 27kg for ram and ewe lambs, respectively, on data prior to or following linear scaling by contemporary group mean. The heritabilities estimated from the full dataset for WWTd, WWTm, LW4, LW5 and LW6 were 0.30{\textpm}0.03, 0.04{\textpm}0.01, 0.49{\textpm}0.02, 0.49{\textpm}0.02 and 0.51{\textpm}0.02, respectively. These traits were highly correlated with both phenotypic and genetic correlations between the direct traits ranging from 84 to 99\%. The same analysis on the two culled datasets resulted in only minor changes the variance components. The correlation between sire breeding values for autumn live weight (LW6) estimated from the full and the two culled datasets were 98.8\% for both models. Autumn live weightbreeding values can be accurately estimated from datasets which include progressive culling if a multivariate live weight analysis is undertaken, and data from all animals measured at each date are used.},
	issn = {1176-5283},
	author = {Jopson NB and McEwan JC and Knowler KJ and Wheeler R}
}
@conference {41698,
	title = {Impact of early age litter size on subsequent litter output in ewes},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {67},
	year = {2007},
	month = {Jan},
	pages = {39-43},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Wanaka},
	abstract = {Data from 28 performance recorded sheep flocks were evaluated to test for effects of litter size early in a ewe{\textquoteright}s life, on subsequent litter sizes. Ewes lambing twins at 2, 3 or 4 years of age had litters with on average 0.04 to 0.08 more lambs at each subsequent lambing than ewes lambing singles. The corresponding increases for ewes lambing triplets versus singles ranged from 0.23 to 0.26, with retention of the effect through successive litters. When data were adjusted to accountfor a ewe{\textquoteright}s lifetime genetic potential for prolificacy, evidence for an antagonistic environmental effecton litter size following a previous large litter was identified. This effect was approximately twice as high for triplets relative to singles (-0.19 to -0.32) when compared with twins relative to singles (-0.09 to -0.18), and declined in its effect on lambings more than one year later. It suggests that preferential treatment ofewes based on their previouslambing performance might improve their subsequent lambing performance. Culling two tooth ewes based on a single lambing record is unlikely to be economically viable, but there may be situations where reduced flushing of two tooth ewes prior to mating might be justified in prolific commercial flocks. The power and limitations of using data from performance recorded flocks to make recommendations relating to management decisions in commercial flocks is discussed.},
	issn = {1176-5283},
	author = {Amer PR and Jopson NB and Cocks J and Scarlet AL}
}
@conference {41676,
	title = {An evaluation of sheep meat genetics in New Zealand: The central progeny test (CPT)},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {66},
	year = {2006},
	month = {Jan},
	pages = {368-372},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Napier},
	abstract = {The New Zealand Central Progeny Test (CPT) was first established in 2001 with the aims of improving the carcass dollar value of sires and establishing genetic links among sire referencing schemes. Over the past three seasons, a total of 72 sires from both terminal and dual purpose breeds have been evaluated for meat genetics at the AgResearch Woodlands farm and the Lincoln University Ashley Dene farm. All progeny, except the 2004 born ewe progeny from the dual purpose sires, were slaughtered at monthly intervals from December to March each year through two Alliance plants, at threshold liveweights of 34kg. Carcass measurements included cut yield (measured by ViaScan grading) eye muscle area, GR, meat pH, meat and fat colour and days to reach an 18kg carcass weight. These measurements were used to calculate three key indices; days to kill, meat value and a combined meat and growth index, as well as individual breeding values. Results showed significant variation among sires for all key traits and that no single ram or breed dominated the top of the indices or breeding values. The range of economic value was approximately $10 across the terminal and dual purpose sires evaluated, demonstrating that considerable potential exists to identify and select better terminal sires. The CPT is now commencing maternal evaluation, using the retained ewe lambs produced from the dual purpose sires. },
	issn = {1176-5283},
	author = {McLean NJ and Jopson NB and Campbell AW and Knowler K and Behrent M and Cruickshank G and Logan CM and Muir PD and Wilson T and McEwan JC}
}
@conference {41526,
	title = {Presidential Address 2004: The changing face of animal science in society},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {65},
	year = {2005},
	month = {Jan},
	pages = {1-3},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {It is a very interesting exercise to go back to the first few editions of our own proceedings and examine the areas of research that occupied the attentions of our members around 60 years ago. While the tools we use today are far superior to the techniques of their day, many of the questions asked have changed little over that time. Our research is still mostly related to how we can make better or more efficient use of our animal and land resources to produce a range of products to suit the markets of the day. However, what has changed significantly over that period is what society considers to be acceptable use of our animal and land resources{\textellipsis} },
	issn = {1176-5283},
	author = {Jopson NB}
}
@conference {41507,
	title = {Comparison of two-stage selection breeding programmes for terminal sire sheep},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {64},
	year = {2004},
	month = {Jan},
	pages = {212-216},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Hamilton},
	abstract = {Two-stage selection is a technique used in animal breeding to make the use of expensive measurements economically viable in a breeding programme. Selection candidates are first screened using inexpensive, but imperfect, predictors of their genetic merit. A selected subset are then evaluated using more accurate, but expensive, measurements and the final selection is made. This study compared the assessment of carcass composition traits using either computed tomography (CT) scanning or progeny testing (with 10 or 20 progeny per sire; PT10 and PT20, respectively) in the second stage of two stage selection systems using quantitative genetic theory. Stage 1 selection was assumed to be based on live weight and ultrasonic predictions of carcass merit. For a genetic correlation of 0.7 between ultrasonic and CT/PT measures, the economic return peaked for progeny test at $2.70 and $2.38 per commercial ewe when 10 and 5\% of the male selection candidates were evaluated in PT10 and PT20, respectively. CT had a greater return at $3.52 per commercial ewe when 20\% of the male selection candidates were evaluated using CT. The results show that given the moderate heritability of carcass composition traits, the reduction in generation interval and the lower cost of evaluation of CT outweighs the increased accuracy of selection and higher mating ratios associated with progeny testing. },
	issn = {1176-5283},
	author = {Jopson NB and Amer PR and McEwan JC}
}
@conference {41439,
	title = {The Alliance Central Progeny Test: Preliminary results and future directions},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {63},
	year = {2003},
	month = {Jan},
	pages = {197-200},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Queenstown},
	abstract = {The Alliance Central Progeny Test (CPT) was established in 2001 with the aims of improving the carcass dollar value of sires under the Alliance grading system and establishing links among ram breeders so Alliance can identify the best rams for their clients.  In the 2002/2003 season 22 terminal sires from nine different breeds were evaluated.   Each ram was mated to 30 ewes at the AgResearch Woodlands research farm.  Progeny numbers for each ram ranged from 13-46.   Initial early results showed that breeding values for weaning weight were well spread among sires (range over 2.5 kg) indicating there were genetic differences among sires used.  Lambs were slaughtered in four slaughter groups between December 16th , 2002 and March 11th , 2003.  Analyses from the full data set will be available from May 2003. The next cycle of the Alliance CPT begins with mating in April, 2003, with an emphasis on dual-purpose sires.},
	issn = {1176-5283},
	author = {Campbell AW and Knowler K and Behrent M and Jopson NB and Cruickshank G and McEwan JC and Wilson T}
}
@conference {41440,
	title = {Genetics of lamb survival},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {63},
	year = {2003},
	month = {Jan},
	pages = {201-203},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Queenstown},
	abstract = {Data from seven commercial New Zealand sheep flocks were analysed to quantify the extent to which lamb survival in New Zealand sheep is influenced by genetic factors. Estimates of direct and maternal genetic variance components, and the effects of inbreeding in either the lamb or the dam on lamb survival, were found to vary significantly across flocks. Direct heritability estimates ranged from 0.008 to 0.070, while maternal heritability estimates ranged from 0.002 to 0.075. Inbreeding in the lamb showed a statistically significant (P<0.05) effect on survival in three of the seven flocks, ranging in value from -0.17 to -0.29\% reduction in lamb survival for a 1\% increase in inbreeding coefficient. Inbreeding of the lamb{\textquoteright}s dam had a statistically significant effect (P<0.05) on survival in two of the seven flocks, taking values of -0.32 to -0.71\% reduction in lamb survival for a 1\% increase in the dam{\textquoteright}s inbreeding coefficient. It is recommended that lamb survival records be transformed to a constant variance within flock and year prior to estimation of breeding values, but that no transformation to either a logit or probit scale within the statistical analysis is required. Inbreeding coefficients for both the lamb and the lamb{\textquoteright}s dam should be included as linear covariates in the mixedmodel analysis of lamb survival breeding values. },
	issn = {1176-5283},
	author = {Amer PR and Jopson NB}
}
@conference {41433,
	title = {Lack of genetic association of markers near the leptin gene with carcass fat content in Coopworth sheep lines selected for and against fatness},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {63},
	year = {2003},
	month = {Jan},
	pages = {176-178},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Queenstown},
	abstract = {Leptin is an important hormone in controlling food intake and energy expenditure in mammalian species. The present study evaluated levels of serum leptin in Coopworth sheep selected for and against subcutaneous fat depth for 10 generations. Significant differences in serum leptin concentrations were found between fat and lean sheep (P<0.05) and between male and female sheep (P<0.01). Serum leptin concentration was positively correlated with carcass fatness and there was a clear relationship between mean progeny serum leptin concentrations and the breeding value for fat. Serum leptin concentrations were greater (P<0.05) in lambs selected from the fat line (2.69ng/ml) than in lambs selected from the lean line (2.18ng/ml). A microsatellite marker, OarCP26, already mapped on sheep chromosome 4 (OAR4) was located in a sheep yeast artificial chromosome (YAC) clone that was positive for the leptin gene (LEP). This confirmed the independent assignment of LEP, mapped using a sheep cell hybrid panel, to OAR4. No significant differences in the allele frequencies of OarCP26 and two other flanking markers (TGLA116 and OarHH335) were detected in the lean and fat selection lines suggesting genes other than leptin are causing the differences in fat between the lean and fat Coopworth lines. },
	issn = {1176-5283},
	author = {Campbell AW and Broad TE and Jopson NB and Burkin HR and Dodds KG and Veenvliet BA and Bain WE}
}
@conference {41437,
	title = {Ram Focus - matching rams to buyer flocks},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {63},
	year = {2003},
	month = {Jan},
	pages = {190-193},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Queenstown},
	abstract = {A new software package has been developed to assist ram breeders to target rams to buyers{\textquoteleft} flocks. "Ram Focus" leads the potential buyer through a short series of questions relating to the buyer{\textquoteright}s current levels of animal performance, aims and future expectations. The answers to these questions are used to calculate economic values for individual traits, which are subsequently combined into an index customised for the buyer. The end result is that Ram Focus reranks the suitability of rams for alternative commercial flocks. Examples are presented of how the suitability of rams changes between commercial flocks, first using examples of differing reproductive performance, and second, differences in expectations of a drench failure.},
	issn = {1176-5283},
	author = {Jopson NB and Amer PR}
}
@conference {41346,
	title = {Dynamic selection for sheep genetic improvement},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {62},
	year = {2002},
	month = {Jan},
	pages = {188-190},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Palmerston North},
	abstract = {Dynamic selection is a process used in livestock improvement programmes to maximise genetic progress while constraining the long term rate of inbreeding. An optimisation algorithm identifies proportions of genes each selection candidate should contribute to the next generation. Application of dynamic selection procedures to select cull and replacement ewes, and then subsequently to select a ram team, was demonstrated using data from a Romney sheep breeder. When compared with selection based on an index of breeding values alone, dynamic selection of cull and replacement ewes reduced the accumulation of relatedness by approximately 85\% of the average annual accumulation from 1994 to 2000. To achieve this, approximately 33\% of the average annual genetic progress in average index value was sacrificed. Using dynamic selection to identify a ram team to be mated to selected ewes resulted in a saving in relatedness by an amount equal to the average annual accumulation from 1994 to 2000 with only a very modest drop in genetic progress of 9\% of the average annual genetic progress in average index value. This study has demonstrated that dynamic selection tools could, when practically applied to sheep breeding populations, provide a transparent and efficient means of managing the tradeoff between rate of genetic progress and rate of accumulation of relatedness. },
	issn = {1176-5283},
	author = {Amer PR and Jopson NB and McEwan JC}
}
@conference {41312,
	title = {The effects of mid-pregnancy nutrition and shearing on ewe body reserves and foetal growth},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {62},
	year = {2002},
	month = {Jan},
	pages = {49-52},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Palmerston North},
	abstract = {In an experiment replicated over three years, ewes were individually fed concentrate diets containing two levels of protein (12 and 18\%) at either maintenance or 1.5 x maintenance from days 35 to 74 of pregnancy, and then at an allowance of approximately 2.0 kgDM/head/day on pasture until parturition. Half of the ewes within each treatment were shorn on day 74. Ewes were CT scanned to measure body composition at days 35, 74, 115 and 140 of pregnancy. Neither protein nor energy level fed during mid-pregnancy had any significant effects on conceptus growth, birth weight or lamb skeletal measurements. Shearing resulted in changes in ewe body composition as well as an increase of 0.36 kg (P<0.01) in lamb birth weights. Lambs from the shorn ewes were 14 mm longer in length (P<0.05) but 8 mm shorter in height (P<0.05) than those from unshorn ewes. Shorn ewes lost 1.3 kg more body fat (P<0.001) than their unshorn contemporaries over the second half of pregnancy. Unshorn ewes lost 0.74 kg of carcass lean over this period, while the shorn ewes gained 0.22 kg (P<0.001). The results show that ewes can be fed maintenance during mid-pregnancy if this allows good quality feed reserves to be built up in front of them for the third trimester. Mid-pregnancy shearing is likely to increase lamb survival in multiple born lambs through higher birth weights.},
	issn = {1176-5283},
	author = {Jopson NB and Davis GH and Farquhar PA and Bain WE}
}
@conference {41239,
	title = {Optimal utilization of genetic resources in aquaculture},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {61},
	year = {2001},
	month = {Jan},
	pages = {35-37},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {This paper uses a vertically integrated salmon farming company as a case study to describe how quantitative genetics  and decision support optimisation tools have been used in an aquaculture breeding programme. The complex tasks of  maximising genetic progress while managing genetic diversity and avoiding inbreeding are considered at two levels. The  first level relates to the management of a nucleus breeding structure for which long term genetic progress and management  of genetic diversity are the primary objectives. The second level relates to the tactical selection among available broodstock  candidates and their mating to avoid inbreeding. The importance of both effective data management systems and practical implementation of theoretical genetic principles is emphasised.},
	issn = {1176-5283},
	author = {Amer PR and Jopson NB and Dodds KG and Symonds JE and Hills J}
}
@conference {41156,
	title = {Lamb and ewe performance of East Friesian x Coopworths relative to pure-bred Coopworths},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {60},
	year = {2000},
	month = {Jan},
	pages = {47-50},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Hamilton},
	abstract = {Purebred East Friesians (EF) sires were used in both the 1996 and 1998 matings (n=2 and 4, respectively) to generate 62 and 66 progeny for the two years. These animals were compared with approximately 1000 COOP lambs in each year for growth, ultrasonic fat and muscle depths, wool, dagginess, host resistance to internal parasites, and reproductive performance. For the 1998 mating, one F1 sire and 24 F1 dams were mated to COOP ewes and rams respectively to produce approximately 73 paternal and 33 maternal backcross progeny. Twenty four EF cross ewes were mated in each of the 1998 and 1999 birth years, and reproductive performance recorded. On average, the EF cross progeny had a live weight advantage (P0.05) after adjustment for live weight, but EF cross progeny had significantly lower C and GR measurements. EF cross progeny had lower fleece weight at 12 months (-0.46kg; P<0.001) than COOP. Average dag score differed between sire breeds with EF cross having lower scores (0.4 verses 1.2) compared to COOP. Sire breed differences in resistance to parasites were not significant. Analysis of the limited EF backcross data indicated positive EF direct and maternal effects for weaning weight, negative EF direct effects for dag scores, and negative EF direct and maternal effects for fleece weight. EF cross ewes performed significantly better (P<0.001) in lambs born per ewe lambing than the purebred COOP for both 2-tooth (2.57 cf. 1.84) and mixed-age (2.76 cf. 1.98) classes. The high lambing percentage in EF cross ewes meant that more than 70\% of mixed-age ewes had three or more lambs per lambing, which could result in management difficulties. There was significant overlap in the sire-breed ranges for all traits, meaning selection of sire was more important than breed selection. },
	issn = {1176-5283},
	author = {Jopson NB and Dodds KG and Knowler KJ and Wheeler R and McEwan JC}
}
@conference {41160,
	title = {Lamb survival traits in Coopworth sheep selected for high or low backfat depth},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {60},
	year = {2000},
	month = {Jan},
	pages = {61-64},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Hamilton},
	abstract = {Consumer preferences for lean healthy meat have driven genetic selection for leanness in the terminal sire and dual purpose sheep industries over the last 20 years. The Invermay Coopworth lean and fat selection lines were established in 1980 to study the effects of selection for live weight adjusted leanness on carcass traits, and the correlated responses in other traits. This paper reports the findings of two year{\textquoteright}s data on lamb survival and performance in the lean and fat selection lines. Records were collected from 817 lambs comprising 325, 337 and 155 from the fat, lean, and a random-bred control line, respectively. Neo-natal mortality was not significantly different between the three lines, with approximately 93\% of lambs born surviving until tagging. Lamb survival from tagging until weaning differed significantly between the selection lines (P<0.05), with fat line animals having 10.9\% better lamb survival than lean line animals (95.5 verses 84.6\%), after adjusting for differences in year, birth weight, birth rank, skin thickness, wool length, age of dam, mothering ability and ewe udder volume. Fat line lambs were 0.9 {\textpm} 0.1kg (mean {\textpm} SEM) lighter than lean line animals, with control line animals intermediate. Udder volume (as measured by water displacement) did not differ between the three lines. Mothering ability (as measured by distance from ewe to the new born lamb during handling in the field) did not differ significantly between the lean and fat lines. Fat line lambs had thicker skins than lean line lambs at the same birth weight (P<0.01), but had no difference in wool length. The differences in lamb mortality between the lean and fat lines cannot be fully explained by differences in birth weight, indicating some physiological difference between the lines affecting survival. },
	issn = {1176-5283},
	author = {Jopson NB and Greer GJ and Bain WE and Findlay JA and McEwan JC}
}
@conference {41138,
	title = {Discriminating among animals for improved rewards from traditional meat cuts},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {59},
	year = {1999},
	month = {Jan},
	pages = {269-271},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {The influence of biological variation on animal numbers meeting specifications based on alternative indicators of carcass merit to GR and carcass weight (CW), and the value of live animal indicators in meeting particular goals were investigated. Percentages of carcasses achieving a two-trait (GR: 5.5 to 9.5mm; and CW: 15.5 to 17.5kg) and a three-trait (GR, CW and various leg lengths: T) specification were analytically derived over multivariate normal distributions. Two {\textquoteleft}populations{\textquoteleft} of sheep were considered; one with a mean CW, GR and T of 14.6kg, 6.8mm and 184mm, respectively, and the second with mean values of 15.5kg, 6.8mm and 186mm. Adding conformational traits reduced the proportion achieving the specification, with the reduction being greater if the correlations between traits were antagonistic. Analysis of potential carcass merit indicators from experimental dissection data indicated that 8\% of the variation in leg weight was associated with sire breed, sire, sex and birth rank effects, while 32\% was associated with animal variations in six linear indicators (high GR, low subcutaneous leg fat depth, high carcass length, T, high proximal leg circumference, and low total length of the leg joint). Together these two classes of indicators accounted for 36\% of the total variation among lambs. },
	issn = {1176-5283},
	author = {Jopson NB and Clarke JN}
}
@conference {40910,
	title = {Plasma potassium - an indicator of protein catabolism in deer?},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {57},
	year = {1997},
	month = {Jan},
	pages = {144-146},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Elevated plasma potassium (K+ ) concentrations well outside the normal range for deer have been reported during the rut. The effects of season and nutrition on plasma K+ concentration were examined in two experiments in farmed red and fallow deer. In Experiment 1 castrate and entire red stags were fed ad libitum on pasture and blood sampled fortnightly over 11 months. Except for a transitory peak at the beginning of Experiment 1, red entires and castrates showed no abnormal plasma K+ concentrations over the 11 month period. In Experiment 2, a castrate group of fallow bucks were fed to lose a similar amount of live weight as entires over the rut. When plasma K+ concentration was expressed as a function of changes in muscle weight there was a significant negative relationship (P<0.05) in the castrates. There was no relationship in the entires, although the measure of change in muscle weight could have been confounded by changes in water content of the musculature over the rut. The occurrence of hyperkalaemia in deer was variable. Further work is required to clarify the conditions that lead to its expression. },
	issn = {1176-5283},
	author = {Jopson NB and Fennessy PF and Thompson JM}
}
