@conference {3672,
	title = {The effect of grazing high-sugar ryegrass on lamb performance},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {75},
	year = {2015},
	month = {07/2015},
	pages = {235-238},
	address = {Dunedin},
	abstract = { A multi-year grazing study was undertaken on three commercial properties in the southern South Island to compare the performance
of lambs grazing high-sugar ryegrass/white clover (HSG) with lambs grazing a standard ryegrass/white clover pasture (SRG).
Cultivars were established in late spring 2012; approximately 400 lambs in each treatment group per property grazed the swards in
autumn 2013 and summer/autumn 2014 at a density of 30 to 35 lambs per hectare. Lambs were weighed regularly throughout the
season; those that reached the desired weight were sent for slaughter. Across both years and properties, lambs grazing the HSG
pasture grew 31 grams per day faster (17\%) on average than those grazing SRG (P<0.001). These lambs were an average of 0.4 kg
heavier in terms of carcase weight at slaughter (P<0.001) yielding 0.2 kg more meat per carcase based on VIAScan yield. These
results suggest that lambs grazing HSG outperform those grazing SRG.},
	issn = {1176-5283},
	author = {Proctor LE and Craig HJB and McLean NJ and Fennessy PF and Kerslake JI and Behrent MJ and Chuah JCL and Campbell AW}
}
@conference {3672,
	title = {Effect of shearing on lamb growth and carcase performance},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {75},
	year = {2015},
	month = {07/2015},
	pages = {215-218},
	address = {Dunedin},
	abstract = { A study was undertaken on three properties throughout New Zealand to determine the impact of shearing on lamb performance
and whether this offered any economic benefit to farmers as a farm-management tool. A total of 1,183 lambs were randomly
allocated to one of four treatments, shorn fasted, bellied fasted, woolly fasted and woolly not fasted. Shorn fasted lambs grew
12 g/d faster than woolly fasted lambs (P<0.05), but at similar rates to bellied lambs and woolly not fasted lambs. There were no
differences among treatments for carcase weight, meat yield or proportion of lambs killed at slaughter. The difference observed in
average daily gain between the shorn fasted and the woolly fasted lambs, and the lack of difference observed between shorn fasted
and woolly not fasted lambs, indicated that while shearing improved lamb growth rates, the weight loss due to fasting overnight
was not overcome by the increased growth rate associated with shearing. While there was no economic benefit associated with
lamb carcase weight or time to slaughter, at a wool price of $5.40 per kg clean, shorn lambs were still of a greater value to farmers
compared to lambs from all other treatments.},
	issn = {1176-5283},
	author = {McLean NJ and Craig HJB and Fennessy PF and Behrent MJ and Kerslake JI and Campbell AW}
}
@conference {79004,
	title = {Does castration status have an effect on the quality of lamb meat?},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {72},
	year = {2012},
	month = {Jan},
	pages = {144-146},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {Consumer demand for leaner lamb meat all-year-round and price incentives to produce heavier carcases means that in New Zealand ram lambs are often being left entire in an attempt to improve lamb growth rates (Fisher et al. 2010). While this offers potential improvements in on-farm returns, there are still perceived concerns in the market place that meat from entire ram lambs of a certain age may be unsatisfactory. Based on the latest scientific evidence (Young et al. 2006; Young et al. 2003) New Zealand processors make no distinction between carcasses from lambs of different genders. However, due to continual perceived concerns from consumers, ... continued},
	issn = {1176-5283},
	author = {Kerslake JI and Hely FS and Maclennan G and Lindsay S and Behrent MR and Campbell AW}
}
@conference {79006,
	title = {Exploring the effects of growth rate and meat yield on lamb meat quality},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {72},
	year = {2012},
	month = {Jan},
	pages = {150-151},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {<p>New Zealand sheep breeding programs currently place high emphases on selection for growth and yield. High growth rates and high meat yield have both been reported as having negative effects on meat quality in pig, beef and poultry (Dransfield \&amp; Sosnicki 1999), probably due to changes in muscle structure and metabolism. In contrast, organic pork has shown to be less tender than conventional pork, which is thought to be due to organic pigs growing more slowly (Therkildsen et al. 2012). It is of importance to evaluate these relationships in lamb.</p>
},
	issn = {1176-5283},
	author = {Campbell AW and Maclennan G and Lindsay S and Behrent MR and Cheong I and Kerslake JI}
}
@conference {75906,
	title = {BRIEF COMMUNICATION: The effects of different forage types on lamb performance and meat quality},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {71},
	year = {2011},
	month = {Jan},
	pages = {208-210},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Invercargill},
	abstract = {<p>Meat quality is made up of a number of traits, with colour at the point of purchase, being perceived as the main indicator of freshness. The traits of aroma, flavour, succulence, and texture influence the eating experience and the probability of repurchase. A number of factors influence meat quality traits, including environmental factors such as... Continued.</p>
},
	issn = {1176-5283},
	author = {Campbell AW and Maclennan G and Judson HG and Lindsay S and Behrent MR and Mackie A and Kerslake JI}
}
@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 {60953,
	title = {Investigating marbling and its relationship to meat quality in New Zealand pasture fed lamb},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {69},
	year = {2009},
	month = {Jun},
	pages = {104-107},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {This is the first report of marbling in New Zealand pasture finished lamb. Marbling and meat quality data were collected on 1,056 loins from pasture finished lambs. Marbling was subjectively assessed on loin cut surfaces, using a five point visual scale (1 = Low, 5 = High), and objectively assessed using computer tomography (CT) scanning. Tenderness was objectively measured on loins that had been frozen. Corresponding loins from the lambs with the fifty highest (High) and fifty lowest (Low) subjective marbling scores were taste panelled after chilled storage. The average subjective scores were 2.94 and 0.94 for the High and Low groups respectively, with the objectively measured CT fat percentages 8.0\% and 10.0\% respectively, both significant differences (P <0.001). Loins from the High group were significantly (P <0.01) more tender than loins from the Low group as assessed objectively, however, this difference was not detected by the taste panel when assessing texture. The taste panel did not detect any significant differences in juiciness, flavour or odour between the two groups. Our findings suggest that this level of marbling in pasture fed, New Zealand chilled stored lamb is insufficient to influence meat quality as assessed by a taste panel. },
	issn = {1176-5283},
	author = {Young EA and Bain WE and McLean NJ and Campbell AW and PL Johnson}
}
@conference {41819,
	title = {Factors affecting colour stability of fresh chilled lamb meat},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {68},
	year = {2008},
	month = {Jan},
	pages = {164-165},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Brisbane, Australia},
	abstract = {An increasing proportion of New Zealand lamb meat is shipped to the European Union market as chilled rather than frozen product, with 29\% exported as chilled product in 2005/06 (Anon, 2006). Once chilled lamb reaches this market it is further processed, with the lamb meat entering the retail market approximately eight weeks after slaughter. A major selection criterion for retail purchasers is the colour of the meat on display. Most consumers prefer bright red ...Continued },
	issn = {1176-5283},
	author = {PL Johnson and McLean NJ and Bain WE and Young E and Campbell AW}
}
@conference {41719,
	title = {Current status of QTL and association studies in New Zealand cattle , sheep and deer},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {67},
	year = {2007},
	month = {Jan},
	pages = {153-159},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Wanaka},
	abstract = {In the last 15 years, a series of experiments has beencarried out to search for quantitative trait loci (QTL) in New Zealand cattle, sheepand deer. A QTL represents the position on a chromosome where there is a statistically significant genetic effecton a measured trait. This paper reviews data published so far from these QTL trials and from various association studies. Although the measurement of traits (or {\textquoteleft}phenotypes{\textquoteright}) and the sampling of tissue or fluid for DNA may be complete, the genotyping of DNA isstill incomplete in most studies; further work may be expected as new DNA genotyping techniques and new genomic data become available, and as funds allow. In cattle, we describe the current status of research for carcass composition, meat quality, pubertal traits, milk yield and milk composition traits, and resistance to facial eczema and bloat. In sheep, we include QTL searches for disease traits (resistance to nematode parasites, facial eczema, ryegrass staggers, and footrot), muscling and carcass composition, reproductive traits, wool traits, and lamb survival. In deer, QTL searches have been carried out for live weights, seasonality and pubertal traits, using measurements from an interspecific hybrid. Generally, significant results have been followed further by finemapping and independent validation, before release to industry. Some of the mapping techniques will be described, with examples. So far, QTLs under study in New Zealand have led to the identification and use of gene-tests or marker-tests for meat tenderness and carcass composition in beef cattle, milk yield and composition traits in dairy cattle, and meat yield \%, muscling and litter size genes in sheep.},
	issn = {1176-5283},
	author = {Morris CA and Campbell AW and Cullen NG and Davis GH and Everett-Hincks JM and Hall RJ and Henry HM and PL Johnson and McEwan JC and Phua SH and Wilson T}
}
@conference {41720,
	title = {LoinMAX and MyoMAX : Taking DNA marker tests from the research environment to commercial reality},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {67},
	year = {2007},
	month = {Jan},
	pages = {160-162},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Wanaka},
	abstract = {Meat yield is an important component of most sheep breeding programmes. To improve meat yield, breeders use a variety of tools including marker assisted selection (MAS). Ovita funded AgResearch to develop two marker tests to assist in selection for superior meat yield. These have been branded MyoMAX TMand LoinMAX TMand originated from quantitative trait loci (QTL)studies over the past decade. In both cases the development of these commercial marker tests  involved refining the QTL locations, identifying informative marker haplotypes and validating these in industry flocks. Both the LoinMAX TMand  MyoMAX TMbeta tests were field validated using a numberof commercial breeders. The validation process showed that the phenotypic effects of both LoinMAX TM and MyoMAX TM were significant in different genetic backgrounds and that there were no negative correlations between the presence of LoinMAX T Mand  MyoMAX TM with other traits, such as meat quality and growth rate. Both LoinMAX TM and MyoMAX TM have now been successfully commercially launched byCatapult Genetics Ltd and are being widely used in industry.},
	issn = {1176-5283},
	author = {Campbell AW and McLaren RJ}
}
@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 {41529,
	title = {Lamb survival: a new examination of an old problem},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {65},
	year = {2005},
	month = {Jan},
	pages = {13-18},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {The overall aim of this project is to identify genetic markers for lamb survival. This paper reports the results from the first stage of the investigation aimed to identify the primary causes of lamb death from parturition to three days of age for highly fecund flocks. Flocks in the study consisted of 9 breeds and 12,000 breeding ewes and were located in New Zealand regions; Southland, Otago and Manawatu. All lambs were tagged and identified to their dam and sire. Lambs dead at birth and up to three days of age were collected (n = 1529), weighed, measured and examined by post mortem to determine cause and time of death. Primary causes of lamb death included: dystocia, starvation/exposure, amnion over nose, organ rupture, disease, and unknown.
 The mean mortality rate from birth to weaning for the 20 flocks studied was 14 {\textpm} 0.6\% (SEM) in singles, 16 {\textpm} 0.3\% in twins and 29 {\textpm} 0.6\% in triplets. The study showed that the predominant primary cause of lamb deaths from parturition to three days of age was dystocia (difficult births). The dystocia rate was highest for dead single lambs (57 {\textpm} 4.2\% SEM) (P < 0.05), where there was an unexpectedly high incidence for dystocia for dead twin (46 {\textpm} 1.7\% SEM) and triplet lambs (48 {\textpm} 2.3\% SEM). This suggests that dystocia as a primary cause of lamb death may be underestimated within highly fecund sheep flocks. The high death rate from dystocia in twin and triplet lambs has not been previously reported and is currently under further investigation.
KEYWORDS: lamb survival; dystocia; post-mortem; cause of death; mortality; genetic; phenotypic. },
	issn = {1176-5283},
	author = {Kerslake JI and Everett-Hincks JM and Campbell AW}
}
@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 {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}
}
