Field test on oil emulsion inactive duck origin ND-ESD-76 bivalent combinet vaccine

Duck origin NDV-D10 and EDS-76GC2 virus strains were propagated by the same embryos and harvested from embryo allantoic fluid after 96 h culture,and used to prepare oil emulsion inactivated ND-EDS-76 bivalent combined vaccine. Two groups of chicken were vaccinated with the newly developed vaccine and ordinary oil emulsion inactivated bivalend combined vaccine respectively,and the difference of antibody titres between the two groups were not significant. The challenge NDV-F48E9 and EDS-76GC2 virulent strains both acted at 30, 180 and 360 d post-immunization. The two vaccinated groups with 60 birds each,selected randomly,showed 100% protectivity at the first two challenge and over 97% and 87% protectivity at last challenge,but not significant difference. The clinical inoculation of layers aged about 120 d with oil emulsion inactivated duck origin ND-EDS-76 bivalent combined vaccine to 2 million single chicken could obtain excellent immune effects of prevent two corresponding field virulent virus infection throughout the laying period.