Investigation Of 4 Virus Reproductive Failure Diseases Among Swine Farms In Gansu

The epidemiological investigation revealed that the major virus reproductive failure diseases widely spreaded among the swine farms in Gansu Province were Porcine Reproductive and Respiratory Syndrome(PRRS),Pseudorabies(PR), Porcine Parvovirus Infection(PPVI)and Japanese B Encephalitis(JE).In these diseases,PR and PRRS have been most spreaded widely,which caused serious abortion of pregnant sows and early death of suckling piglets.They are both the major diseases causing reproductive failure of sows among swine farms.In 2002,there were 10.85%pregnant sows aborted,10.43%reproductive sows died out or were eliminated because of diseases,12.25%newborn piglets have been died before birth.The piglets hadan incidence of 26.12%and a mortality of 12.92%before being weaned.There were 6/14 districts in Gansu (Zhangye,Lanzhou,Dingxi,Tianshui,Baiyin and Jiuquan)most suffered from the virus reptoductive mal-function diseases,whereas Jiayuguan and Gannan the least.The detection of sera antibody for 2754 pigs confirmed 4 virus reproductive failure diseases spreading widely in Gansu.Their sera antibody positive percentage were PRRS 22.50%,PR 38.96%,PPVI 45.32%and JE 15.43%,respectively.The post-invaccinated pigs had an average immune antibody positive percentage of 80.43%.The aetiological study has isolated and identified PRRSV and PRV for the first time in Gansu,it confirmed the existence of the above two diseases in Gansu.The histopathological effects in experiment rabits infected with PRV was observed.