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Title: Genetic parameters and lambda values for post-weaning production traits in Merino sheep
Contributor(s): de las Heras-Saldana, S  (author)orcid ; Gurman, P  (author)orcid ; Swan, A A  (author)orcid ; Brown, D J  (author)orcid 
Publication Date: 2023-07-26
Open Access: Yes
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Appropriate genetic parameters are essential for accurate selection of animals with improved genetic merit for economically important traits. In recent years, Merino breeders have tended to record animals earlier in life making it important to characterise post-weaning measurements. Additionally, genomic information is used in Australian Merino genetic evaluations to obtain more accurate estimations of genetic merit using single-step GBLUP, utilising a weighting factor to partition polygenic and genomic variance, hereby referred to as lambda (λ). This study aimed to estimate genetic parameters and lambda values for production traits measured at the post-weaning stage in Merino sheep. Phenotypic records were obtained at the post-weaning stage for weight (PWT), eye muscle depth (PEMD), fat depth (PFAT), greasy fleece weight (PGFW), clean fleece weight (PCFW), fibre diameter (PFD), fibre diameter coefficient of variation (PDCV), and staple length (PSL). Genetic parameters were estimated with univariate and bivariate analyses, while a genomic REML analysis was performed to calculate the lambda value for each trait. Moderate to high heritability estimates were observed, ranging between 0.25 to 0.56. Genetic correlations were moderately positive between PWT and PCFW, PGFW, PFD, and PSL and negative for PDCV. Lambda values were on average (0.64) slightly higher than the current value used for genomic evaluation (λ = 0.5) and ranged from 0.51 to 0.90. Genetic parameters reported in this study are generally consistent with previous studies and will be used to update the genetic parameters used by Sheep Genetics for the MERINOSELECT analyses.

Publication Type: Conference Publication
Conference Details: AAABG 2023: 25th Conference of the Association for the Advancement of Animal Breeding and Genetics, Perth, Australia, 26th - 28th July, 2023
Source of Publication: Proceedings of the Association for the Advancement of Animal Breeding and Genetics, v.25, p. 318-321
Publisher: Association for the Advancement of Animal Breeding and Genetics (AAABG)
Place of Publication: Armidale, Australia
ISSN: 1328-3227
Fields of Research (FoR) 2020: 300302 Animal management
300305 Animal reproduction and breeding
Socio-Economic Objective (SEO) 2020: 100412 Sheep for meat
100413 Sheep for wool
Peer Reviewed: Yes
HERDC Category Description: E1 Refereed Scholarly Conference Publication
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Appears in Collections:Animal Genetics and Breeding Unit (AGBU)
Conference Publication

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