The Research On Detection Of PRRSV,PRV And PCVⅡ In Cord Blood From Newborn Piglets Apply To Swine Industry

As PRRSV,PCV2 and PRV are important vertically-transmitted viruses,and newborn piglet has no acquired infection,it will make sense that study aims to see whether detection of the viruses in newborn piglet corn blood can be used as indicator for viral infection in sows,and provide scientific basis for swine disease prevention,control and eradication.In this study,ELSA kits for antibodies detection and Q-RT-PCR(Q-PCR)kits for field virus strains detection were applied to detect viruses(PRRSV,PCV2 and PRV)and corresponding antibodies in 59 sow sera samples and the three viruses in 251 newborn piglet cord blood samples collected from 5 pig farms located in Fengxian district of Shanghai in 2015-2016.The sow antibody detection results showed that although the overall positive rates of PRRS and PCVD antibody of the 5 pig farms reached 34/59 and 35/59 respectively,there were marked differences among the 5 pig farms,and 4 farms did not meet the 70% positive rate set by Ministry of Agriculture.Infection rate of PRV field strains was extremely high,one farm arrived at 100%(12/12).The results of detecting viruses in sow sera demonstrated that the positive rate of PRRSV、PCV2 and PRV were relatively low,5.08%(3/59),3.39%(2/59)and 3.39%(2/59),respectively.The results of virus detection of newborn piglet cord blood indicated that the three viruses were detected at different levels,the positive rate of PRRSV、PCV2 and PRV was 8.76%(22/251),3.19%(8/251)and 2.79%(7/251),respectively.The positive detection rate of the three viruses in newborn piglet cord blood was higher than in sow sera,indicating that cord blood detection results could more exactly reflect the real transmission status of the vertically-transmitted virus in pig farms,that is to say,the virus detection results of newborn piglet cord blood can be used as indicator for viral infection in sows.Based on the above detection results of newborn piglet cord blood,ultra pre-immunization of newborn piglets with live vaccines through dropping noses was carried out in the two pig farms with relatively high positive rate,good effect achieved.