| 25 pregnant cows were highly immunized with the germs of E.coli﹑S.dysenteriae﹑S.typhi and triple vaccines . serum and milk were collected at different experimental time, the antibody levels of antigens in serum and milk were detected by micro agglutination , the dynamical changes were described in order to supply the theoretical basis for the further research and development of immune milk. Standard bacteria E.coli44210﹑S.dysenteriae51105﹑S.typhi50089 from China center of medical bacteria collection were dealed with activation ﹑cultivation ﹑inactivation﹑concentration and supplement etc. At last obtained alumina gel vaccine and oil emulsion vaccine. Activated bacterial liquid was scribbled to the cultural utensil with nutrient agar, after some operations, got antigens stored at 4℃ and prepared for diagnosis.Every antigen and positive serum were diluted by certain proportion and through micro agglutination in order to ascertain the suitable concentration. The results were showed as follows: 40 hundred million bacteria every millimetre for E.coli﹑30 hundred million bacteria every millimetre for S.dysenteriae and 40 hundred million bacteria every millimetre for S.typhi.In the experiment, 25 pregnant cows were divided into 5 groups randomly, 5 cows every groups and the experimental groups of A﹑B﹑C﹑D were respectively immunized with E.coli﹑S.dysenteriae﹑S.typhi and triple vaccines, the group of E as the control. All the experimental groups were immunized at different times : the first immunization was disposed with inactivated alumina gel vaccine via intramuscular injection at the day 60 before parturition, after 10 days, the second immunization was disposed as the first ways, the third immunization was disposed with inactivated oil emulsion vaccine via intramuscular injection at the day 35 before parturition.The time of collect samples of blood was fixed at the juncture before every immunization and in the 0d﹑3d﹑7d﹑14d﹑21d﹑28d﹑35d﹑42d﹑49d﹑56d﹑63d﹑70d﹑77d﹑84d after parturition, serum was obtained by the centrifugation and stored at 4℃ after making its energy deprived in 56℃ for 30 minutes. The time of collect samples of milk was the same as samples of blood after parturition, whey was obtained by the centrifugation and stored at 4℃ for the further observation. the specific antibody levels were detected by micro agglutination . For cows immunized with E.coli ,the results were showed as follows: on the parturition, antibody levels of serum and whey were simultaneously attained to the climax in the experimental group and control group, the experimental serum and whey were 211.6 and 29.8 respectively, the control serum and whey were 28.4 and 27 respectively. hyper antibody levels of whey in the experimental group can be detected for about 80 days significantly(P＜0.01), at the same time, the antibody in whey was less 2 titers than in serum during the whole experimental time, this is consisted with the report from Wang chun-feng. For cows immunized with S.dysenteriae,the results were showed as follows: on the parturition, antibody levels of serum and whey were simultaneously attained to the climax in the experimental group and control group, the experimental serum and whey were 212.2 and 210.4 respectively, the control serum and whey were 26.4 and 24.6 respectively, hyper antibody levels of whey in the experimental group can be detected more than 80 days significantly(P＜0.01), at the same time, the antibody in whey was less 2 titers than in serum during the whole experimental time.For cows immunized with S.typhi ,the results were showed as follows: on the parturition, antibody levels of serum and whey were simultaneously attained to the climax in the experimental group and control group, the experimental serum and whey were 210 and 28.2 respectively, the control serum and whey were 27.2 and 25.2 respectively, hyper antibody levels of whey in the experimental group can be detected more than 50 days significantly(P＜0.01), at the same time, the antibody in whey was less a... |
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