Genome-wide association study of health and production traits in meat sheep

K Kaseja; S Mucha; J Yates; E Smith; G Banos; J Conington

doi:10.1016/j.animal.2023.100968

Genome-wide association study of health and production traits in meat sheep

Animal. 2023 Oct;17(10):100968. doi: 10.1016/j.animal.2023.100968. Epub 2023 Aug 29.

Authors

K Kaseja¹, S Mucha², J Yates³, E Smith³, G Banos², J Conington²

Affiliations

¹ SRUC Easter Bush, Roslin Institute Building, Edinburgh EH25 9RG, UK. Electronic address: Karolina.Kaseja@sruc.ac.uk.
² SRUC Easter Bush, Roslin Institute Building, Edinburgh EH25 9RG, UK.
³ The British Texel Sheep Society, Stoneleigh Park, Warwickshire CV8 2LG, UK.

PMID: 37738702
DOI: 10.1016/j.animal.2023.100968

Abstract

Genotypes are currently widely used in animal breeding programmes to enhance the speed of genetic progress. With sufficient data, a Genome-Wide Association Study (GWAS) can be performed to identify informative markers. The aim of this study was to investigate the genetic background of health (footrot and mastitis) and production (birth weight, weaning weight, scan weight, and fat and muscle depth) traits using the available phenotypic and Single Nucleotide Polymorphism (SNP) data collected on the UK Texel sheep population. Initially, 10 193 genotypes were subject to quality control, leaving 9 505 genotypes for further analysis. Selected genotypes, recorded on four different Illumina chip types from low density (15 k SNPs) to high density (606 006 SNPs), were imputed to a subset of 45 686 markers from 50 k array, distributed on 27 chromosomes. Phenotypes collected on 32 farms across the UK for footrot and mastitis and extracted from the UK National database (iTexel) for the production traits were used along with pre-estimated variance components to obtain de-regressed breeding values and used to perform GWAS. Results showed three SNPs being significant on the genome-wise level ('OAR8_62240378.1' on chromosome 8 for birth weight, 's14444.1' on chromosome 19 for weaning weight and 's65197.1' on chromosome 23 for scan weight). Fourteen subsequent SNPs were found to be significant at the chromosome-wise level. These SNPs are located within or close to previously reported QTLs impacting on animal health (such as faecal egg count or somatic cell count) and production (such as body or carcass weight and fat amount). These results indicate that the studied traits are highly polygenic with complex genetic architecture.

Keywords: Footrot; Genome-Wide Association Study; Live weight; Mastitis; Small ruminants.