Antibiotic treatments and somatic cell count as phenotype to map QTL for mastitis susceptibility in Holstein cattle breed

Mastitis is one of the most significant diseases affecting dairy cattle profitability. A genome wide association study (GWAS) was performed using selective genotyping approach to identify Quantitative Trait Loci (QTL) associated with mastitis susceptibility. According received antibiotic treatments in all their productive life, 52 lactating cows have been classified resistant (no therapy and low SCC) susceptible (more than treatment high mastitis. Genotyping animals NEOGEN’s GGP Bovine 100K SNP chip QTL were identified comparing SNPs allelic frequencies between two groups. 26 related susceptibility 9 chromosomes. The use data, coupled SCC from milk recording, improved cow’s classification accuracy individuals. For this reason, mandatory recording active January 2022, could be a new source information improve genetic selection for resistance.