Control And Eradication Of Pseudorabies In Commercial Pig Farms

Pseudorabies, also called Aujeszky Disease, Porcine Herpes Virus 1(PHV-1), is an acute, frequently fatal disease by pseudorabies virus with a worldwide distribution that affects many domestic and wild animals, and it threats the swine industries much, can also harm the nervous system and immune system of swine, leading to secondary infection of other pathogens, and great economic loss of the swine industries. The research was carried out in order to build PRV gE antibody negative pig farm, and finally control pseudorabies, promote the development of swine industry.1. Investigation and analysis of wild type PRV infection Five pig farms of A, B, C, D, E in Henan province were detected of PRV gE antibody by using the PRV gE ELISA kit from IDEXX company. Among these pig farms, breed pigs in A, B pig farms were PRV gE antibody negative, but pigs of growth were detected few positive pigs, and the positive rates were 1.6% and 1%, respectively. C, D, and E were high gE antibody positive Pig farms, which positive rates were up to 19.6%,21.3% and 20%, respectively. It shows they were seriously infected by wild type PRV.2. Strengthening immunization. Pigs in high PRV gE antibody positive pig farms were immunized by using high-grad PRV gE gene-deleted vaccines. The immune procedure was as follows:all the pigs were immunized PRV gE gene-deleted vaccines, at an interval of two weeks, at a dose of two portions with big pigs and one portion for little ones. After immunization, pigs of the whole group were sampled for detecting the level of gE antibody, and data were analyzed in order to make optimal immune procedure.3. Removal of pigs carrying out wild type PRV, and cultivate healthy ones. with regard to PRV low positive pig farms, once positive pigs were found, slaughtered and buried, and then given conventional immune. With regard to high seropositive pig fields, we used gene-deleted vaccine to vaccinate pigs, and after it, we used PRV gE ELISA kit to test antibody level of the whole group. If the serologically positive rate is lower than 15% in sows and 20% in fattening swines, the seropositive pigs were slaughtered, and only seronegative sows were introduced in and regular immune procedure was conducted. The regular immune procedure was as follows: pregnant sows were vaccinated twice with a dose of 1 portion from 3 to 8 weeks before parturition at an interval of three weeks, non-pregnant sows and sows of backup were vaccinated one times, at a dose of 1 portion before breeding, and then vaccinated one time with a dose of 1 portion from 3 to 8 weeks before parturition. Piglets produced by vaccinated sows were immunized one time with 1 portion at about 8 to 12 weeks old. Piglets produced by non-vaccinated sows were immunized one time with 1 portion at 3 weeks old. Breeding boars were vaccinated 1 portion every four weeks.4. Make eradication measures and put it into practice. According to the investigation results of wild type PRV infection, the optimal immune procedure made, the measures and effects of removal of the infected pigs, and statistics analysis of the detected data and together with biosafe measures, produce management, such as disinfection, hygiene, prohibition of dog and cat, and eradication of mice, and etc, The immune state, control and eradication of PR were concluded in our province. after three years of experimental research, we successfully eradicate PR in four pig fields. The PRV gE antibody seropositive rate of A pig field decreases from 1.6% to 0; and pig field B from 1% to 0; pig field C from 19.6% to 0; pig field D from 21.3% to 0. Finally the breed pigs were all eradication to seronegative pigs, which was greatly enhance the production and economic effect of these pig farms.