[Study on the relationships between polymorphisms of CXCR2 gene and milk quality and mastitis of dairy cow].

PCR-SSCP was applied to analyze the polymorphisms of CXCR2 gene and its relationships with milk quality and mastitis in 160 cattle samples including Holstein dairy cow, Simmental dairy cow and Tongjiang cattle. The results showed that there were 3 SNP loci in CXCR2 gene, which located at 684 bp, 777 bp, 861 bp, respectively. Five alleles (A, B, C, E and F) were determined based on the 3 SNP loci. The genotypes for each locus were BC and CC, AA and AB, CC and BC at 685 bp, 777 bp and 861 bp, respectively. Results also demonstrated that genotypes BC, CC and FF were probably relevant with mastitis, but AA, BB and EE may resist the mastitis of cattle. The genotypes AA, AB and EE may have better milk quality (extremely significant difference or significant difference) than other genotypes.