Study And Application On Control Strategy And Surveillance Of Wild Virus Infection Of Porcine Pseudorabies In Swine Farms Of South Henan

To find out the distribution of Porcine pseudorabies in scale pig farms of Henan province, 3158 sera samples from 336 medium and small-scale farms and 238 free-range farms of 4 districts were detected with the IDEXX indirect ELISA kit. The serological data were analyzed systematically. The results showed that the PRV infection was popular in the most of medium and small-scale pig farms of Henan province, the average PRV positive rate in sera samples was 26.76%, and the PRV positive rates in 4 districts (Zhumadian, Pingdingshan, Xinyang and Nanyang) were 30.05%, 20.22%, 29.87% and 22.94% respectively. The population positive rates in different ages of pigs (pregnancy pigs, suckling pigs, nursing sow, nursery pigs and breeding boar ) were 32.74%, 25.63%, 22.91%, 10.32% and 10.16% respectively, and the maximal population positive rate in abortive breeder was 45.13%. Furthermore, PRV infection was detected in all farms, and the average PRV positive rate in free-range farms was 37.25%, which was significantly higher than that of the medium and small-scale farms(21.74%, p<0.05).The average positive rates of medium and small-scale farms had great difference range from 16.23% to 27.05%, and the average positive rates of free-range farms had great difference range from 25.71% to 46.44%. And the positive rate of sows was 34.19%, and the positive rates had difference in sows of different parity, the positive rate of sows with 1 to 4 parities was higher than the average positive rate, but the positive rates of sows with 4 or more parities was lower than the average positive rate. And the positive rates of sows with twice immunization were higher than that of sows with three immunization.A PCR detection method was developed based on the gE gene of high rirulent PRV strain, which could differentiate PRV gE- vaccinated swine from wild virus infected swine. It could be a fast and specific detection method for PRV. The PCR positive rate in material in sick pigs was 25.81%, which suggested the PRV infection was still popular in south Henan.A experiment with strategy of immunization, surveillance and eradication technique was put into practice in 8 medium and small-scale pig farms from 2007 to 2008 years, according to foreign successful experience of Porcine pseudorabies eradication program relying on pseudorabies gene deleted vaccine. The result showed that the PRV positive rates of breeder in all 6 pig farms reduced gradually from the first detected positive rate (12%, 7.5%, 10.63%, 24.67%, 17% and 30%) to the third detected positive rate (0%, 0%, 0%, 0%, 0% and 0%). Which provided a scientific and new way to control the Porcine pseudorabies.Conclusively, Porcine pseudorabies is still popular in south Henan, and it is feasible to control and eradicate Porcine pseudorabies in some medium and small-scale pig farms through scientific prevention strategy including immunization, feeding management and closed type management, biological safety, young swine segregated earlier weaning technique, all small unit enter and all exit technique,dry nurse of second stage etc.