建立高水平猪流行性腹泻病毒母源抗体方法的对比分析OA

To explore effective methods for establishing maternal antibodies against porcine epidemic diarrhea virus(PEDV),this study compared the immunization effects of feedback exposure plus inactivated tissue vaccine with those of commercial vaccine plus inactivated tissue vaccine.The decay of PEDV immunoglobulin A(IgA)in colostrum and milk of feedback-exposed sows was analyzed,the duration of mucosal immunity was assessed,and the effect of inactivated tissue vaccine on PEDV IgA content in milk was examined.The results showed that the immunization strategy of feedback exposure combined with inactivated tissue vaccine induced significantly higher levels of IgA antibodies in sows than the commercial vaccine plus inactivated tissue vaccine strategy(P<0.01).The content of PEDV IgA in milk decreased gradually with lactation time but still provided immune protection for piglets.PEDV IgA content in colostrum of sows were significantly higher than those in gilts(P<0.05).After a single feedback exposure followed by continuous parity-based immunization with inactivated tissue vaccine,high-level expression of PEDV IgA in colostrum was maintained for 5-6 parities.In sows that received inactivated tissue vaccine immunization for two consecutive parities after feedback exposure,PEDV IgA content in colostrum showed no significant change compared with two parities earlier(P=0.075).However,in sows that ceased parity-based vaccination after feedback exposure,PEDV IgA content in colostrum significantly decreased after two parities(P<0.01).These findings indicate that feedback exposure combined with continuous parity-based inactivated tissue vaccination can effectively induce high levels of PEDV IgA antibodies,and ongoing parity-based immunization is critical for maintaining antibody levels.This study provides a valuable reference for establishing high-level maternal immunity against PEDV.