Genome-wide association study for conformation traits in Ayrshire cattle

The genetic improvement of cattle is able to provide the highest economic efficiency. Animals with best external features often have the highest indicators of productivity and nonspecific resistance. In order to identify single nucleotide polymorphism (SNP) markers and genes, potentially responsible for conformation traits of Ayrshire cattle, we conducted a genome-wide association study (GWAS). Blood samples were collected from 495 first-calf Ayrshire heifers. For all animals, a linear assessment was carried out, which consisted of 17 conformation traits and 13 exterior flaws. Our study revealed a total of 43 SNPs on chromosomes BTA1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 14, 16, 18, 19, 22, 25, 27, and 29 associated with conformation traits, four of which have met the significance threshold. Among these four significant SNPs, genes associated with exterior flaws such as tilted udder floor and weak loin and SNPs associated with weak back were identified. The markers and genes identified in the corresponding genomic regions are promising candidates for further investigation of the biological processes involved in cow exterior formation and function. The results obtained, including the MYO1B gene associated with weak loin, PEPD and ZFC3H1 genes related to tilted udder floor, and EDNRB gene associated with weak back can be effectively used as molecular markers in genomic selection programs.