We have analysed the missense SNPs belonging to six genes (CXCR2, CXCL8, TLR4, BRCA1, LTF, BOLA-DRB3) and identified one marker (rs110124025) in BOLA-DRB3 that was associated with frequency of mastitis and with the number of affected quarters. Here, CXCR2 is linked to mastitis.