| Classical swine fever(CSF),High pathogenicity porcine reproductive and respiratory syndrome(HP-PRRS)and porcine foot-and-mouth disease(FMD)were severe infectious diseases that threaten the development of the swine industry,which were listed as compulsory immunization diseases by China.The workload and labor intensity was very large in traditional immunization ways,and both of the work efficiency of multiple immunization and utilization rate of vaccines were low,which lead to the basic density of immunization was low and immune effect wasn't ideal,can not reach the target that the density of herd immunity was more than 90% and qualified rate of immune antibody was more than 70% accord with national requirements,which caused the serious consequence that the diseases were still continued to occur.Therefore,it was urgent to develop efficient and safe immunization ways which was suitable for the local situation.This experimental study on combined immunization method was carried out based on the regional characteristics and the situation of farmers of Urumqi area in Xinjiang,provided new methods for improving the immune efficiency and immune effect of major diseases of live pig in Xinjiang especially Urumqi.The vaccine safety and maternal antibody duration tests of CSF live vaccine(spleen and lymph tissue origin),HP-PRRS live vaccine and porcine FMD inactivated vaccine were carried out in this study.The feasibility of multi-point synchronous immunization and specific immune process were explored by the tests of step by step immunization alone and injection in to different points(two points,three points)simultaneously of the vaccines.By clinical observation and ELISA detection for antibody,only a small number of pigs had mild stress reaction after vaccination,and they all returned to normal without treatment.The duration of the maternal antibody of CSF was 28-32 days,HP-PRRS was 30-35 days,porcine FMD type o was 29-34 days.On 90 th day after the first immunization with booster immunization with five different combinations of three vaccines,the average qualified rate of antibody was 88.3%,86.7%,86.7%,88.3%,88.3% respectively.The results showed that safety of the three vaccines was better,immune interference phenomenon did not appear of different combinations immunization.The adverse reaction and mortality of pigs were not increased after immune injection at dividing points combined with three vaccines,which save time and effort,was safety and high efficiency.The duration of maternal antibody in piglets was related to the level of maternal antibody in sows and whether the piglets eat the colostrum.The maternal antibody levels in piglets reached the highest in 1-7 days,then the maternal antibodies gradually attenuated,the level of maternal antibody in piglets was negatively correlated with the growth of piglets.It has been identified that the optimal time of first immunization was 28-35 days combined immunization of three vaccines according to the duration of maternal antibody.The immune effect of five different kinds of vaccine combination was basically identical,and the effective protection time of antibody was at least 90 days.The economical and effective immunization way for Urumqi was as follows: three vaccines were injected into three points simultaneously,the basic immunization and secondary strengthen immunity were combined,and the immunizing dose need not be increased.The results of this study show that the technological method of injection into three points simultaneously of the three severe infectious diseases vaccines of pig was safe and feasible,scientific and efficient,the intensity of labor is low.It is convenient for clinical operation and application,and the immune effect is ideal,which is suitable for popularization and application in large area of the city.It will have great value in stabilization of the CSF,HP-PRRS and porcine FMD and avoiding the regional epidemic situation outbreak in Urumqi. |
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