Restriction fragment length polymorphism in the exon 2 of the BoLA-DRB3 gene in Chinese Holstein of the south China

The genetic diversity of the exon2 of BoLA-DRB3 (BoLA-DRB3.2) in Chinese Holstein cattle of the south China was investigated by hemi-nested polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. Six, four and eleven RFLP patterns were found after digestion with the restriction enzymes Hae III, Bst YI and Rsa I, respectively. The DNA sequence showed and twenty- five DRB3.2 alleles. GLM model analysis indicated that lactation and calving season have positive correlation with SCC (Somatic Cell Count) (p<0.01), BoLA-DRB3.2*3, *8, *18 and *26 were associated with lower SCC (p<0.01). The present findings concluded that mastitis is a severe hinder of milk production and technology. Therefore, future re-searches should focus on associations of mastitis with BoLA haplotypes rather than single BoLA genes