Relationship Between Cattle DRB3.2 Gene And Mastitis Caused By Main Pathogenic Bacteria

Mastitis caused by lots of factors degrades the production trait of cattle and cause large economic loses for the dairy industry in China. It is difficult to prevent or treat for there are too many pathogeny could induce disease. It becomes a new way to prevent mastitis through molecular breeding to prevent the disease, as developing of biotechnology. Bovine Lymphocyte Antigen genes have affluent polymorphism and get attention of experts. Some scholars have studied the relationship between mastitis and affectability to SSC or some pathogenic bacteria and so on. This study carried out the relationship between affectability of three major pathogenic bacteria led to mastitis and polymorphism of BoLA-DRB3 exon2 with 224 China Holstein cattle.1 Detection of mastitis and identification the major pathogenic bacteria224 cattle chosen from milking China Holstein cattle of Jinan and Dongying city indentified with mastitis detection reactant made in Lanzhou Prologue Veterinarian Research Centre. There is 72.32% cattle infected mastitis in these cattle. There are 11 types pathogenic bacteria isolated and identified. Staphylococcus aureus, Escherichia coil, Streptococcus agalactiae are major pathogenic bacteria and reach to 86.21% of all pathogenic bacteria. The three major pathogenic bacteria also were identified with PCR technology.2 PCR-RFLP analysis of BoLA-DRB3.2 geneThe polymorphism of BoLA-DRB3.2 in China Holstein cattle were analyzed by PCR-RFLP. The results revealed DRB3.2 gene has extensive polymorphism, 4 alleles and 4 genotypes digested with enzyme Haeâ…¢; 3 alleles and 4 genotypes digested with enzyme Rsaâ… . The Genotypic frequency and gene frequency of DRB3.2 gene in China Holstein Cattle was calculated. Statistical results showed that polymorphic locus for Haeâ…¢and Rsaâ… of China Holstein DRB3.2 locus didn't fit with Hardy-weinberg equilibrium. 3 Analysis of correlationThe date of types of pathogenic bacteria led to mastitis and gene types were conformed by SAS analysis software. The correlation between the gene types of BoLA-DRB3.2 gene and the susceptivity of mastitis caused by Staphylococcus aureus, Escherichia coli and Streptococcus agalactiae were analyzed. The result show that the Haeâ…¢BC gene type were closely related to the mastitis caused by Staphylococcus aureus; the Rsaâ… EE and the Rsaâ… EF gene type was closely related to the mastitis caused by Escherichia coli. This study offered the date of the relationship between affectability of mastitis caused by three major pathogenic bacteria and polymorphism of BoLA-DRB3 exon2 for selecting the molecular markers to prevent mastitis through genetic resistance.