Isolation And Identification Of Newcastle Disease Virus From Goose,Preparation Of Inactivated Vaccine And Optimization Of Immune Programme

Goose Newcastle disease(ND) is a kind of goose acute, potent and highly contagious disease caused by avian paramyxovirus type Ⅰ (AMPV-1). The diseases induced by NDV have many types and the different damage levels. It is the most harmful avian virus disease causing huge economic losses to the global. At present, the chicken ND attenuated vaccine is widely used in China to produce antibodies against the virus to prevent ND. However, many researches showed that to immune the goose with the chicken ND attenuated vaccine wasn’t able to prevent ND. The isolation and identification of goose NDV to develop the inactivated vaccine is scheduled. In addition, it is need to establish the scientific immunization program optimization due to the gooses with different immunostate in the different regions.A viral isolate was obtained from the dead goose of Mei He kou, Jilin Province in this experiment. The9-11day old chick embryos chanlleged with the viral isolate resulted in death. The result of serological testing after the collecttion of the allantoic fluid of dead chick embryos showed that the allantoic fluid can agglutinate chicken1%red blood cells, and this aggregation can be inhibited by ND standard positive serum but not EDS-76, A1(H5, H7and H9) standard positive serum. The virus was tested by RT-PCR. The size of amplified gene fragement by RT-PCR was consistent with the expected size, and thus viral isolate was determined as NDV, which was named as MHK-1. The chick embryo mean death time (MDT),1-day-old susceptible chicks intracerebral pathogenicity index (ICPI) and chicken half of the infective dose (ELD50) were determined according to the criteria and methods of OIE. The results was MDT=55.2h, ICPI=1.76and ELD50=10-8.3/0.2mL.Ultimately the viral isolate was determined as the virulent NDV.In order to control the incidence and prevalence of goose Newcastle disease in Mei He kou effectively, the ND inactivated vaccineuse was developed with the virulent NDV in the region. After physical properties testing, sterility testing, security testing and immunization effectiveness of inspection, it is proved that the vaccine is in line with the vaccine production standards for its stability and security. The vaccine was used to immune9-11day old stating geese, and a high antibody titer was gained after two weeks. Three weeks passed, the protection rate of this vaccine which was used to immune the geese was100%, and the control group were all died. Three kinds of immunization program were scheduled and optimized, and it was indicated that the test group of goose ND inactivated vaccine+Lasota-clone30was the best immunizat-ion program. This kind of immunization program had the peisisted protection, and the reinforcement of the immunity should be carried out.