Effect of BoLA-DRB3 exon2 polymorphisms on lameness of Chinese Holstein cows.

The involvement of bovine lymphocyte antigen (BoLA) in immune system and its role in susceptibility/resistance to infectious diseases has been extensively studied. However, few studies have been conducted to investigate the association between BoLA and gait scores. Our objective was to investigate whether polymorphisms in BoLA gene are associated with susceptibility of lameness in 435 Chinese Holstein cows. Genotyping of the BoLA-DRB3.2 gene was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) with three restriction endonucleases (BstUI, BstYI and HaeIII). The relationship between the polymorphisms in BoLA-DRB3.2 gene and gait scores was analyzed by least-squares linear model. The gait score was non-significant among all five BstUI-RFLP and BstYI-RFLP genotypes. However, analysis of seven HaeIII-RFLP genotypes revealed a significantly higher gait score for AB genotype than others. In conclusion, BoLA-DRB3.2 may be a candidate gene for lameness susceptibility in Chinese Holstein cows.