Analysis Of Antibody Growth And Decline In Pigs,cattle And Sheep Of Foot-and-Mouth Disease Type O,type A And Type Asia I Trivalent Inactivated Vaccine

Foot-and-mouth disease is a kind of heat,acute,highly contactable infectious disease which can cause cloven-hoofed animals to fall ill.Once the disease outbreak,the incidence of the disease would reach 100% and the mortality would range from20% to 50%,seriously affecting healthy development of the global animal husbandry.In order to control foot and mouth disease,developed countries kill infected animals in a comprehensive way,while the main way china adopts in preventing and controlling foot and mouth disease is vaccine immunization.Cattle is the most susceptible animal to FMDV,especially cow,with the characteristics of detoxification.Compared with other cloven-hoofed animals,clinical symptoms of sheep with the disease is not obvious,so that it is not easy to be found in the presence of infection,while pigs are very sensitive to FMDV and sick pigs can produce a large number of air-soluble virus.The amount of toxin expelled by a sick pig is equivalent to that expelled by 1000 ~ 3000 heads of sick cattle,so detecting the law of growth and decline of the antibody of pigs,cattle and sheep as well as infection condition is of great indicative role for the prevention and control of FMD.3ABC is a nonstructural protein encoded by FMDV and its antibody is used to diagnose and distinguish infected and non-infected animals.Pigs with different ages were selected as the experimental object in the study,immunized according to immunization program.While detecting the titer change of antibody,the relationship between the immunization frequency of the foot and mouth disease and the positive rate of 3ABC,as a focus,was studied.The results showed that there was no obvious linear relationship between the immunization frequency in pigs and the 3ABC positive rate.For the cattle the immunization was carried out on the 0th day and the 157 th day respectively.The blood samples were collected at 4 time points after immunization and the changes of O,A and Asia I antibodies were detected.The results showed that the vaccine in the experimental group just at the time or 157 days after immunization could produce antibody which was at more than 1:64 titer,effectively preventing the occurrence of foot and mouth disease in cattle herd.For the sheep the immunization was carried out on the 0th day and the 177 th day respectively.The blood samples were collected at 6 time points after immunizationand the changes of the three types of antibodies were detected.The results showed that the vaccine in the experimental group just at the time or 157 days after immunization could produce antibody which was at more than 1:64 titer,playing a better protective effect on sheep.Combined with the production practice,the research did a in-depth study on the law of growth and decline of the foot-and-mouth trivalent inactivity vaccine antibody of pig,cattle,and sheep farm,which had a certain theoretical significance and practical value.