. Alignment of sequences showed that there were 5 important mutation points that could be used to differentiate between susceptible and resistant alleles. In addition, the mastitis-susceptible associated alleles tended to increase milk yield, whereas mastitis-resistant associated alleles tended to decrease milk yield. Allele DRB3*10 had the greatest effect on increasing milk yield with moderate resistance to clinical mastitis and could be used as a potential marker for selection in dairy genetic evaluation.