Study On The Species, Biology Feature And Immunity Of The Pathogen Of The Clinical Cow Mastitis

96 milk specimens of the clinical cow mastitis were collected from some large dairy farms, 195 strains of bacteria were isolated from 90 milk specimens, but no strains of bacteria were isolated from the other 6 ones. There were 52 strains of Staphylococci, 96 strains of Streptococcus and 27 strains of E coli, the positive rate was 26.27%, 49.23%, and 13.85% respectively, other 20 strains was 10.25% . The total positive rate of Staphylococci,Streptococcus and E coli was 89. 75% which were the principal pathogen of the clinical cow mastitis.We selected the bacteria which have strong virulence by test and studied on the chiasm of the antigen of the principal pathogen bacteria by agglutination test and two-way agar diffusion test. According to the result of chiasm of the antigen, two strains of Streptococcus numbered 0-2 and 14, two strains of Ecoli numbered 8 and A., and one strains of Staphylococci numbered 11 were selected. Four different immunogens were preparated from these bacteria and immunized the dairy cows. We collected milk and blood specimens after immunizing at different time and detected the IgG in the milk by one way agar diffusion test, studied on the variability of IgG between the immunized groups and the control group by SPSS software ,the result was significant (P<0.01) . We detected the specific antibody level in the blood by the indirect ELISA, the immunized groups were higher than the control group.We observed and recorded the morbidity rate and milk production both in the immunized groups and the control group. We studied on the variability of the average milk production of each cow per month in all test groups at the...