Diagnosis And Purification Technologies Of Porcine Pseudorabies In Moderate-scale Farms

Pseudorabies virus(PRV)is a herpes virus which can infect pigs,cattle,sheep,other livestock and wild animals.PRV mainly damagethe nervous system and reproductive system,reduce the performance of livestock and even lead to animal deaths.According to incomplete statistics,there have been 44 countries and regions around the world reported the occurrence of PRV,which caused up to billions dollar economic losses.Pigs are natural hosts of PRV,and it can infect the pigs at all stages.Newborn piglets usually showed neurological symptoms,and the mortality rate is extremely high.Pregnant sows,boar breeding usually showed disorders based.Growing fattening pigs usually showed respiratory symptoms.Once infected PRV,it is difficult to remove it,because of its rapid transmission,spread a wide range.PRV has been classified as a category Ⅱ infectious disease by the InternationalOfficeofEpizootics(OIE).Attenuated live PRV vaccineshas contributed effectively to the control of pseudorabies virus(PRV)during the past 30 yearsin China.However,at the end of 2011,a severe PRV outbreak took place in many PRV vaccinated pigs farms and spread quickly in the pig herds in China and caused great economic losses to the swine industry.Researches showed that the current PR outbreaks were caused by PRV variants so the traditional Bartha-K61 vaccine could not provide complete protection against the current prevalent PRV variants in China.In this study,three pig farm was divided into three groups according to the positive rate of PRVof census results:high risk of PRV,medium risk of PRV and low risk of PRV.The development and implementation of PRV purification were procedured,respectively,and within three years,all of the three pig farms were successfully purified PRV.