Genome-wide association for somatic cell score in Holstein cows raised in tropical conditions

Abstract Text: Mastitis is the most expensive inflammatory disease that affects milk quality in dairy cattle. Somatic cell score (SCS) is a good indicator of the milk quality and it can be used to identify resistant animals. Identification of genetically resistant animals can be reduce economic losses associated to mastitis. Genome-wide association study (GWAS) using Bayes C method was performed to identify regions associated to SCS in 673 Holstein cows reared in tropical conditions. The animals were genotyped by using BovineLD BeadChip (6K) and GWAS was performed using GS3 software. Four SNPs showed suggestive associations with SCS on the BTA6, 8, 14 and 15. Some of these regions were previous detected QTL, but other are new. These results highlighted the importance to identify regions which are related to important economic traits in dairy cattle, under tropical conditions, enhancing the knowledge of genetic architecture of these traits.

Keywords: genomics, mastitis, snp