Effect of Breeder Vaccination on Immunization of Progeny Against Newcastle Disease

摘要: Two experiments were conducted to determine the effect of breeder vaccination program and maternal antibody on efficacy Newcastle disease immunization 1-day-old chicks. Experimental protocol was same for both. In first experiment, broilers from breeders that 32 weeks old, in second 50 old. Breeders received three live virus (NDV) vaccines either a killed vaccine at 18 or continual boosting 60-to-70-day intervals through lay. Broilers vaccinated 1 day age with commercial coarse-spray machine; they bled, sera examined against NDV, challenged virulent NDV 2, 4, 6 age. higher chicks younger given inactivated vaccine, experiment older vaccines. Higher resulted fewer vaccine-induced reactions, less shed, decreased duration immunity vaccination.