Mastitis is the most common production disease in the dairy sector worldwide, its incidence being associated with both cows' exposure to bacteria and the cows' genetic make-up for resistance to pathogens. The objective of our study was to analyse 89 missense SNPs belonging to six genes (CXCR2, CXCL8, TLR4, BRCA1, LTF, BOLA-DRB3), which were found to be associated with genetic resistance or susceptibility to mastitis. A total of 298 cattle (250 Romanian Spotted and 48 Romanian Brown) were genotyped by Kompetitive Allele Specific PCR (KASP) and a chi-squared test was used for genetic association studies with clinical mastitis. A total of 35 SNPs (39.3%) among the selected 89 SNPs were successfully genotyped, of which 31 markers were monomorphic. The polymorphic markers were found in two genes: TLR4 (rs460053411) and BOLA-DRB3 (rs42309897, rs208816121, rs110124025). The polymorphic SNPs with MAF > 5% and call rates > 95% were used for the association study. The results showed that rs110124025 in the BOLA-DRB3 gene was significantly associated with mastitis prevalence (p ≤ 0.05) in both investigated breeds. Current results show that the SNP rs110124025 in the BOLA-DRB3 gene can be used as a candidate genetic marker in selection for mastitis resistance in Romanian dairy cattle.
Keywords: KASP; Romanian Brown; Romanian Spotted; mastitis; polymorphism.