Different Immunization Ways Of PCV-2 And M.hyo Inactivated Vaccines To The Piglets And Immunological Effect Assessments

Porcine circovirus disease(Porcine circovirus disease,PCVD)is caused by Porcine circovirus type 2(PCV-2),which leads to porcine multisystem diseases.Mycoplasmal pneumonia of swine(MPS)is a chroni infectious disease caused by Mycoplasma hyopneumoniae(M.hyo).PCVD and MPS both are immunosuppressive viruses,which induce secondary infection,mixed infection and serious disease of respiratory system;reduce the feed conversion rates;increase the mortality and cause economic losses in the swine industry.Vaccine immunization is the main measure for prevention and control of these two diseases.To assess the immunological effect of different immunization ways by PCV-2 and M.hyo inactivated vaccines of a certain factory in Sichuan,and provide reference to the immunization procedures of PCV-2 and M.hyo vaccines.Fifty 14-day-old piglets with negative serum of PCV-2 and M.hyo(both antigen and antibody)were chosen and randomly divided into five groups(?,?,?,? and ?).Group ?was a control;group ? vaccinated with the PCV-2 inactivated vaccine only;group ? vaccinated with the M.hyo inactivated vaccine only;group ? immunized with the PCV-2 and M.hyo inactivated vaccine respectively(combined immunization);group ? immunized with the mixture of the PCV-2and M.hyo inactivated vaccines(mixed immunization).The initial and secondary immunization were at 14 and 28 days old.Then the antibody level of PCV-2 and M.hyo were tested by ELISA at 0 d,14 d,21 d,28 d,35 d and 42 d after immunization;the weight of piglets in the beginning and the end of test were recorded;the experimental data was analyzed using SPSS,and we compared the immune performance between the groups.For the further assessment of mixed immunization of the PCV-2 and M.hyo inactivated vaccines,the healthy piglets of the sow in one farm were divided into two groups(A and B),1311 piglets in group A applied the mixture of PCV-2 and M.hyo inactivated vaccines of a certain factory,1252 piglets in group B applied different supplier's PCV-2 and M.hyo vaccines,and the corresponding antibody level was tested at 75 days old.Then we assessed the production performance of piglets from the aspects of weight changes and death status,in the stages of weaning to nursery and weaning to slaughter,in batches,and comprehensively compared the immune efficacy of the two groups.The results shown the PCV-2 and M.hyo inactivated vaccines of a certain factory were safe and no immune side effects,the swinery had normal food intake,shapes,and weight.Software analysis displayed the average weight of each group had few differences,group? gained 19.02 Kg in average,which was 1.24 Kg more than group?,and group?,?,?had little difference in weight,the differences of the weight change in five groups were not obvious(P>0.05).The ELISA results showed PCV-2 antibody produced faster than M.hyo antibody,group ? and ? got both PCV-2 and M.hyo 100% positive in 28 and 35 days after initial immunization,respectively.Group ?,?,?reached 100% positive of PCV-2 in28,28,35 days after immunization,and reached 100% M.hyo positive in 21 days after immunization.Combined immunization had slightly higher PCV-2 and M.hyo antibody level than independent and mixed immunization.But on the whole,the immune effect of the groups were not obvious(P>0.05).The clinic practices shown: in the test of the random serum samples,the antibody positive rate of both PCV-2 and M.hyo could reached 90.9%(10/11)in group A,but in group B this could only be 27.3%(3/11).The production performance of piglets from weaning to nursery stage shown the death rate of group A,B were 0.76%(10/1311),2.40%(30/1252)respectively;the average weight in group A was 0.612 Kg more than group B when the pigs moved to nursery.And in the stage from weaning to slaughter,the death rate of group A,B were 1.08 %(6/557),2.90 %(16/552)respectively;the average weight in group A was 3.04 Kg more than group B when the pigs became ready for slaughter.The clinic practices results proved group A that applied with PCV-2 and M.hyo inactivated vaccines of a certain factory mixed immunization had advantages over group B that applied with different supplier's PCV-2 and M.hyo vaccines.Results declared that PCV-2 and M.hyo inactivated vaccines of a certain factory were safe and effective,and independent,combined and mixed immunization had similar immune effect and low mutual interference.When PCV-2 and M.hyo inactivated vaccine are both needed,we recommend to adopt the mixed immunization,which can reduce stress response,improve animal welfare,and save time and labour,and is safe and effective,which can produce immune protection persistence.This study provide references for pig farms with scientific,reasonable and efficient vaccination program.