@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 = {Sheep divergently selected for methane yield showed differences in meat fatty acid composition},
	journal = {New Zealand Journal of Animal Science and Production},
	volume = {81},
	year = {2021},
	month = {01/2022},
	pages = {173-178},
	address = {Online},
	abstract = {The purpose of this work was to investigate whether 18-month-old rams from the methane selection lines differed in their levels of soft tissue depth over the 12th rib (GR, as a proxy of carcass fatness) intramuscular fat (IMF), and the fatty acid composition of IMF. The rumen is the site of microbial biohydrogenation of consumed plant fatty acids and synthesis of unique microbial body fatty acids. It is known that there are differences in the microbiome and fermentation characteristics of sheep selected for and against methane production (methane selection lines). When comparing the high and low lines several differences were found. Rams from low-methane-yield-selection lines tended to have lower GR (P<0.06) than those from high line rams, but there was no evidence for a difference in levels of IMF between the lines (P=0.77). There were, however, many significant differences in the fatty acid composition (as a \% of total fatty acids) of the IMF between the lines. The IMF from the low-methane-yield line had a significantly (P<0.05) higher proportion of branched-chain fatty acids, and fatty acids that are associated with the early stages of the biohydrogenation pathways in the rumen, specifically conjugated linoleic acid (CLA) and C18:1 t11 but with less C18:0 stearic acid (the end product of biohydrogenation) and a significantly higher proportion of C16:1 t9 which is produced through β-oxidation of C18:1 t11. These results provide insight into how differences in sheep from the methane-yield selection line may influence the fatty acid composition of their fat.


Keywords: Methane; sheep; intramuscular fat; fatty acid composition},
	issn = {1176-5283},
	author = {PL Johnson and Agnew M and Jonker A and Hickey SM and McEwan JC and Bryson B and Dodds KG and Rowe SJ}
}
@conference {3672,
	title = {BRIEF COMMUNICATION: Developing genomic tools in the New Zealand Deer Industry},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {75},
	year = {2015},
	month = {07/2015},
	pages = {91-93},
	address = {Dunedin},
	abstract = { },
	issn = {1176-5283},
	author = {Rowe SJ and Clarke SM and Van Stijn TC and Hyndman DL and Ward JF and McEwan KM and Dodds KG and McEwan JC and Newman S-AN and Asher GW}
}
@conference {3672,
	title = {BRIEF COMMUNICATION: Genetic control of the rumen microbiome in sheep},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {75},
	year = {2015},
	month = {07/2015},
	pages = {67-69},
	address = {Dunedin},
	abstract = { },
	issn = {1176-5283},
	author = {Rowe SJ and Kittelmann S and Pinares-Pati{\~n}o CS and Wood GR and Dodds KG and Kirk MR and Ganesh S and Hickey SM and Janssen PH and McEwan JC}
}
@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 {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}
}
