Comparison Of The Immunogenicity Of Inactivated Vaccines Of Porcine Circovirus Type 2

Porcine circovirus type 2(PCV-2)infection can cause multiple porcine diseases,which including postweaning multisystemic wasting syndrome(PMWS),porcine dermatitis and nephropathy syndrome(PDNS),proliferative necrotizing pneumonia(PNP),porcine respiratory disease syndrome(PRDC),etc.Vaccine immunization is the main measure for prevention and control of the diseases.In the study,the immunogenicity of 4 different kinds of commercial porcine circovirus type 2 vaccines was examined in a PCV-2 positive farm for the selection of the vaccine in the future.The main study content is as following:Three hundred forty-five 14 to 21 days-old piglets were randomly assigned to five groups with 69 piglets in each group.Group 1 was immunized with the imported PCV2 subunit vaccine(Cap-BLG).Group 2-4 were immunized with inactive PCV2 vaccine PCV2-SH and PCV2-CP,and epitope PCV2 vaccine(PCV2-EP),respectively.Group 5 was used as no vaccine control.After immunizations,the morbidity,mortality,daily weight gain and feed conversion ratio were observed and statistical analyzed.The results were showed as following:(1)In lactation stage,there was no significant difference in gross weight gain and average daily gain ratio of the pigs in the different immune groups and control group.But the zero culling rates of the pigs in PCV2-SH group and PCV2-EP group were lowest.(2)In nursery stage,the weight gain in PCV2-EP group was significantly higher than those in PCV2-SH group,PCV2-CP group and control group(P<0.05).The culling rate in PCV2-SH group and PCV2-EP group was the lowest.The mortality of pigs in PCV2-SH,PCV2-CP and PCV2-EP groups was lower than that in Cap-BLG group.And the feed intake of pigs in group PCV2-EP was the highest.There was no significant difference in the feed conversion ratio among the four immune groups,but which were slightly higher than that in the control group.(3)In fattening stage,PCV2-SH group provided the highest weight gain and followed by PCV2-EP group.The mortality and culling rate in PCV2-SH group and PCV2-EP group was lower than that in group PCV2 subunit vaccine(Cap-BLG)(import vaccine).The feed intake of PCV2-SH group was highest and followed by PCV2-EP group.But no significant difference of feed conversion ratio was found among the five groups.(4)In nursery and fattening phase,the input-output ratio in PCV2-EP group was the highest and followed by PCV2-SH group.In conclusion,PCV2-EP and PCV2-SH vaccine could provide better immune protection against PCV2 infection and get high rate of economic return.It suggested that those vaccines could be used to control PCV2 associated disease.