@article {3672,
	title = {Genome-wide association studies for milk traits in New Zealand dairy sheep},
	journal = {New Zealand Journal of Animal Science and Production},
	volume = {82},
	year = {2022},
	month = {01/2022},
	pages = {64-68},
	address = {Online},
	abstract = {The New Zealand dairy sheep industry has grown markedly in the last decades. With better genetics and management, companies have been able to improve key production traits. This study aimed to identify single nucleotide polymorphisms (SNPs) associated with milk traits in dairy sheep. We performed genome-wide association (GWA) analyses for milk yield, fat and protein content using data from commercial farms. We used 54,698 milk yield records and 24,891 fat and protein records from 4,590 and 2,823 ewes, respectively. Phenotypes were collected between August 2018 and April 2021 across three locations in New Zealand. They were adjusted for flock, age, lactation, lambing date, weeks in milk and permanent environment. Animals were genotyped with commercial SNP chips with 13,759 markers available after quality control. GWA models included the genomic relationship matrix, three principal components and genomic inflation correction for the p-values. We found four genome-wide significant associations for milk yield. These variants were mapped to eight genes, PDZRN4 (intron), EDEM2, PROCR, MMP24 (intron), EIF6, FAM83C, UQCC1, and HDAC9 (intron). Of these, PDZRN4, HDAC9 and MMP24 were associated with milk traits in previous studies. No significant associations were found for fat and protein content. Genes shown here are promising candidate genes, requiring validation in independent samples.},
	issn = {1176-5283},
	author = {Costilla R and Chan PB and Mcrae KM and McEwan JC and Dodds KG and Newman SA and Baird HJ and Henry H}
}
@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 = {INVITED REVIEW: A review of the current sheep industry in New Zealand and opportunities for change to meet future challenges},
	journal = {New Zealand Journal of Animal Science and Production},
	volume = {81},
	year = {2021},
	month = {01/2022},
	pages = {1-15},
	address = {Online},
	abstract = {<p>Like all farming systems, sheep operations face increasing economic, environmental, cultural, and social challenges, including climate change and consumer expectations about their food. Genetic improvement has the potential to help with these challenges. This review explores the importance of genetic improvement on welfare and disease traits in meeting these challenges. For all wool breeds, there is a need for traits such as being polled, having a short tail and having a bare breech and a bare belly to ensure an ethical outcome. Sheep that either seasonally lose their fleece, or do not grow wool, represent an opportunity. Predicted climate change poses significant animal-health challenges, including the internal parasite Haemonchus contortus, facial eczema, flystrike and pneumonia, that are likely to encroach on a wider geographic range. Given consumer expectations around reduced chemical inputs and improved animal welfare, genetic improvement will play a critical role in developing sheep that are more tolerant to such health challenges. While several key physical characteristics required for the future exist in minor breeds currently in New Zealand, their performance under a range of New Zealand commercial farming conditions has not been evaluated. Some overseas breeds, such as Katahdin and Barbados Blackbelly, may offer opportunities. Consideration needs to be given to the use of novel gene pools both within and outside the New Zealand sheep industry for it to be able to meet future challenges. To achieve this end, more information is needed about the overall merit of these novel breeds, to be able to identify the best strategy to take towards breeding sheep that address the future needs of the New Zealand sheep industry. Keywords: sheep; genotypes; breeding; future</p>
},
	issn = {1176-5283},
	author = {PL Johnson and Newman S-AN and Mcrae KM and van der Weerden T and Brown M and Scobie DR}
}
@article {3672,
	title = {BRIEF COMMUNICATION: Potential alterations in New Zealand sheep, beef cattle and deer numbers due to climate change: what can genetics offer?},
	journal = {New Zealand Journal of Animal Science and Production},
	volume = {78},
	year = {2018},
	month = {07/2018},
	pages = {146-150},
	address = {Lincoln},
	abstract = {Many producers of red meat in New Zealand run enterprises consisting of a mix of sheep, beef cattle and deer, with obvious
differences in species ratios across regions when aggregated. The aim of this study was to use these regional species ratios to
predict livestock number changes in New Zealand in response to climate change. Simple linear regression was performed using
mean temperature and species ratio (sheep, beef cattle and deer) for each region. The slopes of these linear equations were used
to estimate {\textquotedblleft}business-as-usual{\textquotedblright} for each region in year 2100 under different models of climate change. An overall decrease in
sheep and deer numbers by up to 38\% and 75\%, respectively, is predicted, along with an increase in beef cattle numbers by up to
60\%. Genetics provides an opportunity to select for animals that are adapted to the changing environment through reproductive
plasticity, disease resistance, and heat tolerance, and therefore to moderate these predicted changes.},
	issn = {1176-5283},
	author = {Mcrae KM and Rowe S and McEwan JC}
}
@conference {3672,
	title = {BRIEF COMMUNICATION: An update on genetic parameters for facial eczema tolerance in sheep},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {76},
	year = {2016},
	month = {07/2016},
	pages = {43-45},
	address = {Adelaide},
	abstract = {Facial Eczema (FE) is a metabolic disease resulting
from liver and bile-duct damage, caused by ingestion of
the mycotoxin sporidesmin A, found in the spores of the
fungus Pithomyces chartarum. Risk of FE is associated
with temperature, humidity and dead leaf matter (Mitchell
et al. 1959; Brook 1963; Di Menna \& Bailey 1973). While
FE is predominantly prevalent in the North Island of New
Zealand, climatic change projections indicate that there
will be an increase in the geographical spread of the fungus
and associated sporidesmin, resulting in FE spreading to
regions that are currently unaffected (Dennis et al. 2014).
Clinical FE is characterised by photosensitisation
due to liver injury; however, reduced production (Smith
2000) and reproduction (Moore et al. 1983; Mcmillan et al.
1988; Morris et al. 1991) is also observed in both clinically
and sub-clinically affected animals. The heritability of
liver damage at slaughter post-sporidesmin challenge was
estimated to be 0.42 {\textpm} 0.09 (Campbell et al. 1981). In the
live animal, serum gamma glutamyltransferase (GGT)
collected 2 to 3 weeks after sporidesmin challenge can
be used as a measure of liver damage (Towers \& Stratton
1978). Romney FE selection lines, initially selected for
resistance or susceptibility on the basis of liver damage,
were established in 1975...},
	issn = {1176-5283},
	author = {Mcrae KM and Cullen NG and Amyes NC and PL Johnson}
}
@conference {3672,
	title = {BRIEF COMMUNICATION: Preliminary estimates of genetic parameters for adult dag scores in New Zealand sheep and their relationship with juvenile measurements},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {76},
	year = {2016},
	month = {07/2016},
	pages = {144-145},
	address = {Adelaide},
	abstract = {The accumulation of faecal material around the breech
area of sheep (dags) is of interest to the New Zealand
sheep industry for a variety of reasons, including financial
penalties for presenting animals with dags at slaughter,
reduced wool value, increased risk of flystrike and the
labour cost associated with dagging both lambs and adult
ewes (Pickering et al. 2012). Currently, dag scores at
both three (DAG3) and eight (DAG8) months of age are
routinely measured, and analysed in Sheep Improvement
Limited (SIL). However, there are currently no formally
published estimates of the genetic relationship between dag
score as a lamb and dag score as an adult (DAGA) in the
New Zealand sheep population. Adult dag score has been
found to be highly repeatable between 12 months to two
years of age (R = 0.42) and between two and three years of
age (R = 0.44) in different strains of Merino sheep (Larsen
et al. 1995).
Currently within SIL, the estimated breeding values
(EBVs) calculated from DAG8 measures are reported
as the adult dag score EBVs. There are now, however,
multiple flocks recording adult dag score in the SIL
database. An analysis of the correlation of adult dag score
with DAG8 and DAG3 would confirm if the current SIL
model is appropriate for reporting adult dag EBVs, or if the
model needs revising to include adult dag measures and its
correlations with DAG3 and DAG8.},
	issn = {1176-5283},
	author = {Mcrae KM and Dodds KG and Newman S-AN and Brito LF and Pickering NK and McEwan JC}
}
@conference {75915,
	title = {BRIEF COMMUNICATION: Arapawa: a novel New Zealand sheep breed of distinct origin},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {71},
	year = {2011},
	month = {Jan},
	pages = {248-250},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Invercargill},
	abstract = {Arapawa sheep are a feral breed found on Arapawa Island in the Marlborough Sounds, New Zealand. Their origin is not documented, but it is thought to be one of the oldest feral flocks in New Zealand dating back to approximately mid 1800s (Orwin et al., 1984). There are numerous... Continued},
	issn = {1176-5283},
	author = {Young EA and Kijas JW and Mcculloch R and Scobie DR and Mcrae KM and Pickering NK and Dodds KG and McEwan JC}
}
