No association between β-Defensin 103B (DEFB103B) single nucleotide polymorphisms (SNPs) or haplotypes and Staphylococcus aureus mastitis in Holstein cattle

Abstract Text: Staphylococcus aureus infection was previously monitored in two populations of Holstein cattle from Saskatchewan (Canada) and Pennsylvania (USA). All cows were genotyped for seven SNPs present in the 5’UTR of cattle DEFB103B. Cows with the diploid haplotype 1/4 (P = 0.053) tended toward an increased risk of mastitis in the Saskatchewan population. Cows with the diploid haplotype 4/4 (P = 0.06) tended toward a decreased risk of mastitis in the Pennsylvania population. Relative risk and odds ratio results indicated that haploid haplotypes 2 and 3 in the Saskatchewan population, and haploid haplotypes 1 and 4 in the Pennsylvania population were less susceptible to mastitis. However, because the results of the Fisher Exact test, the Relative risk and the Odds ratio were not consistent between the two populations, these DEFB103Bhaplotypes cannot be used as markers to select for mastitis resistance.

Keywords: Beta Defensin gene family, CNV, dairy cattle