@article {3672,
	title = {Impact of winter near-maintenance or non-restricted feeding on growth and intramuscular fat content of yearling rams},
	journal = {New Zealand Journal of Animal Science and Production},
	volume = {81},
	year = {2021},
	month = {01/2022},
	pages = {141-145},
	address = {Online},
	abstract = {There is increased interest in genetic improvement in intramuscular fat in lamb due to its positive association with meat quality. Live-animal measures such as ultrasound or computed tomography scanning can enable genetic selection. The optimum time at which such measurements should take place is unknown. This study investigated levels of intramuscular fat in year-old rams. During the winter of 2020, ram lambs were fed on either a just-above-maintenance pasture diet (JAM) (n=119) with a target weight gain of 50 g/day, or non-restricted feeding (GAIN) (n=120) with a target weight gain of 180-200 g/day, with all rams slaughtered after 10 weeks of differential feeding. Both groups of rams were fed a ryegrass-dominant pasture. The target for the GAIN group was achieved with an average growth rate of 182{\textpm}42 g/day (range 76 to 293 g/day), however, for JAM group the average growth rate was 24{\textpm}64 g/day (range -212 to 126 g/day), with a third of the animals losing weight. The JAM group were split according to whether they had gained (JAM {\textendash} Gain) or lost weight (JAM {\textendash} Loss) for the analysis. There were differences (P<0.001) at the time of slaughter in early spring in carcass weight between groups (23.7{\textpm}0.35, 19.5{\textpm}0.40 and 17.0{\textpm}0.47 kg for GAIN, JAM {\textendash} Gain and JAM {\textendash} Loss respectively). The levels of intramuscular fat were low across all groups compared to levels normally observed in 6-8-month old ram lambs and with further differences (P<0.001) between the three groups (2.1{\textpm}0.08, 1.9{\textpm}0.09 and 1.4{\textpm}0.10 kg for GAIN, JAM {\textendash} Gain and JAM {\textendash} Loss respectively). More work is required to understand management systems that allow improved expression of the trait. Additionally, careful consideration needs to be given to winter grazing management of all young stock, as there is considerable variability in individual animals handling of winter maintenance feeding.

Keywords: lamb; maintenance feeding; intramuscular fat},
	issn = {1176-5283},
	author = {PL Johnson and Knowler K and Mcrae KM and Bain WE and Pile G and Craigie CR and Rowe SJ}
}
@article {3672,
	title = {Predicting internal adipose from selected computed tomography images in sheep},
	journal = {New Zealand Journal of Animal Science and Production},
	volume = {80},
	year = {2020},
	month = {09/2020},
	pages = {113-116},
	address = {Online},
	abstract = {Dairy cattle preferentially lay down internal (INT) (e.g., kidney) adipose relative to sub-cutaneous adipose (SCF) tissue, but this
pattern is the opposite in beef cattle, which preferentially deposit adipose subcutaneously. It is proposed that these differential
patterns of fat distribution evolved to match the different production drivers of these breeds. As the New Zealand sheep industry
has become more diverse in terms of breeds and production systems, the role that differential adipose distribution could play in
supporting different production systems is of interest. The potential to use commercially obtained Computed Tomography (CT)
images (i.e., six images, selected to predict carcass attributes in the live animal), to additionally predict INTF in addition to carcass
fatness, was investigated using a full set (i.e., 30-32) of CT images available on 50 maternal ewe lambs. The R2 between the fulland
sub-set of images for absolute amounts ranged from 0.25 for bone to 0.92 for SCF, with INTF 0.77 (P<0.001). When adjusted
for total weight, correlations were slightly reduced, but still supported the ability of the analysis of the six images to accurately
identify animals with differential fat distribution. Future work will include analysis of a further 550 animals from the same data
set to determine the genetic correlation between the full and subset of images. If successful, adipose distribution can be predicted
from existing and future commercial CT data sets and used to investigate its genetic and phenotypic relationship with production
traits.

Keywords: internal adipose; subcutaneous adipose; computed tomography},
	issn = {1176-5283},
	author = {PL Johnson and Juengel JL and Bain WE}
}
@conference {3672,
	title = {Variation in total body adipose and adipose partitioning in maternal sheep estimated using computed tomography scanning},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {76},
	year = {2016},
	month = {07/2016},
	pages = {122-125},
	address = {Adelaide},
	abstract = {In sheep, decreasing adipose or fat is desirable in prime lambs; however, adipose also has a role in the productive capacity of the
maternal ewe. There are three main depots of adipose within the body of a live animal: sub-cutaneous, intermuscular and internal
(or visceral). To understand if differences exist between animals in adipose deposition and partitioning, a study was undertaken using
37 New Zealand composite-breed maternal ewes, scanned using computed tomography on three occasions from nine through
to 17 months of age. The images produced were processed to estimate the weight of subcutaneous, intermuscular and visceral
adipose (along with lean and bone), with the weights then expressed as a percentage of total adipose to investigate partitioning.
The raw average total body adipose remained proportionate across the three scans at approximately 32\% of total empty body
weight. The resulting data were analysed using a REML variance components analysis in Genstat. The repeatability of fat distribution
across the three scans was high, ranging from 0.77 for proportion of intermuscular adipose through to 0.83 for proportion of
subcutaneous adipose. The component Animal was significant for all traits indicating between animal variation in partitioning of
adipose between the depots within individual animals. Cumulatively, these results demonstrate that there is variability in adipose
deposition and partitioning in New Zealand sheep. If under genetic control, variability that could be exploited to optimise adipose
to best meet the requirements of prime lamb production and maternal ewes.},
	issn = {1176-5283},
	author = {PL Johnson and Bain WE and Johnstone P and Bixley M and Knowler K}
}
@conference {3672,
	title = {BRIEF COMMUNICATION: Genetic parameters for growth, carcass and meat quality traits in New Zealand sheep},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {75},
	year = {2015},
	month = {07/2015},
	pages = {94-96},
	address = {Dunedin},
	abstract = { },
	issn = {1176-5283},
	author = {Brito LF and Miller SP and Clarke SM and Dodds KG and Bain WE and Lee MA and Pickering NK and McEwan JC}
}
@conference {3678,
	title = {BRIEF COMMUNICATION: An exploratory investigation of the effects of selection for divergence in methane emissions on rumen digesta and carcass traits in 8-month old sheep},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {74},
	year = {2014},
	month = {06/2014},
	pages = {142-144},
	address = {Napier},
	abstract = {Global agriculture accounts for approximately 14\% of anthropogenic emissions. In New Zealand, methane emissions from ruminants comprise 31.5\% of the total emissions (Ministry for Environment 2009), therefore, any future mitigation of emissions could have substantial economic implications for the agricultural sector. Reducing emissions from ruminant livestock without affecting animal production against a rising demand for animal products is challenging (Clark 2009). Measurements carried out over the last 15 years have shown a common feature of individual animal variation in methane emissions (Pinares-Pati{\~n}o et al. 2011b). Recently it has been shown that enteric methane emissions from sheep are both heritable and repeatable (gCH4/day 0.29 {\textpm} 0.05; repeatability 0.26 {\textpm} 0.02), whether expressed as gross emissions (g/d) or methane yield (emissions per unit of feed dry matter intake, g/kgDMI; Pinares-Pati{\~n}o et al. 2013). This makes breeding an attractive mitigation strategy for the lowering of enteric emissions from ruminant livestock given animal production performance is not affected (Pinares-Pati{\~n}o et al. 2011a)...},
	issn = {1176-5283},
	author = {Elmes SN and Bain WE and Greer GJ and Hickey SM and Young EA and Pickering NK and Rowe SJ and Knowler KJ and Pinares-Pati{\~n}o CS and McEwan JC}
}
@conference {69487,
	title = {Carcass linear measurements as predictors of meat yield in lambs determined by VIAscan},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {70},
	year = {2010},
	month = {Jun},
	pages = {130-132},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Palmerston North},
	abstract = {Lambs yielding proportionally more lean meat are desirable to processing companies as they have a greater quantity of saleable product which also meets market demand withoutthe need for further processing. The quest for higher yielding lean lambs has seen a change in the lamb carcass grading system from classification on carcass weight and the GR measurement (total tissue depth above the 12th rib, 110 mm from the midline) (Kirton, 1989) to using imaging systems such as VIAscan{\textregistered}. VIAscan{\textregistered} is a two dimensional imaging system that estimates lean content of the carcass (Hopkins et al., 2004).},
	issn = {1176-5283},
	author = {Bain WE and McEwan JC and McLean NJ and PL Johnson}
}
@conference {60952,
	title = {Effect of sex on colour and pH of chilled lamb loins : Brief Communication},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {69},
	year = {2009},
	month = {Jun},
	pages = {101-103},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {With more chilled lamb being exported from New Zealand, there is interest in factors affecting the quality of the chilled product. Two key factors are ultimate pH and the redness of the meat when on display for sale. The possible effect of the sex of the lamb on these quality traits is of interest to the industry (Meat and Wool New Zealand, 2006). A number of studies have reported non-significant differences between ewe and ram lambs at moderate carcass weights of approximately 18 kg, for pH and colour measured within 24 hours post-slaughter... Continued },
	issn = {1176-5283},
	author = {Bain WE and McLean NJ and Young EA and PL Johnson}
}
@conference {60980,
	title = {Genetic parameters for colour stability of chilled lamb : Brief Communication},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {69},
	year = {2009},
	month = {Jun},
	pages = {220-222},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	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 (Meat and Wool New Zealand, 2006). New Zealand{\textquoteright}s lamb export markets are located such that the chilled product travels large geographical distances via freighted shipping, taking six to twelve weeks to reach the destination. Once chilled lambs arrives at its destination it is further processed and packaged to specification for retail sale. Shelf life and colour stability are particularly important for this... Continued },
	issn = {1176-5283},
	author = {McLean NJ and PL Johnson and Bain WE and Greer GJ and Dodds KG}
}
@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 {41785,
	title = {Effect of MyoMAX on carcass lean and fat},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {68},
	year = {2008},
	month = {Jan},
	pages = {43-44},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Brisbane, Australia},
	abstract = {Previous research has identified quantitative trait loci (QTL) for increased lean meat yield and decreased fat in similar regions of sheep chromosome 2, in New Zealand and Belgian Texels (Broad et al., 2000; Johnson et al., 2005; Laville et al., 2004; Marcq et al., 2002). In the case of the Belgian Texels it has been demonstrated that a single G to A transition ...Continued },
	issn = {1176-5283},
	author = {Bain WE and PL Johnson and Greer GJ and Dodds KG and McLean NJ and McLaren RJ and Galloway SM and Van Stijn TC and McEwan JC}
}
@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 {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 {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 {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 {41172,
	title = {Search for a locus near to myostatin that increases muscling in Texel sheep in New Zealand},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {60},
	year = {2000},
	month = {Jan},
	pages = {110-112},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Hamilton},
	abstract = {In close collaboration with three Texel breeders, we initially genotyped 36 rams with 5 DNA microsatellite markers that are known to map around the myostatin gene in sheep. Of these 36 rams, progeny of 12 polymorphic sires (4 from each flock) were selected for further analysis. This selection was made on the basis of each sire producing more than 40 offspring which were accompanied by parentage records, live weights at weaning and 8 months of age, and ultrasonic measurements of fat depth and rib-eye muscle dimensions. Final progeny numbers from the sires chosen ranged from 45 to 115 per sire. The data was analyzed by regressing the observed measurements on the probability of which paternal grandparental chromosome was inherited at the myostatin locus. The results suggest that the region of the sheep genome near the myostatin locus affects muscling (P<0.05) and fat depth (P<0.05) in the progeny of 4 of 12 sires tested. },
	issn = {1176-5283},
	author = {Broad TE and Glass BC and Greer GJ and Robertson TM and Bain WE and Lord EA and McEwan JC}
}
