The Observation for Interference Effect of FP Vaccine and ND Vaccine Immunization on ND HI Antibody

The experiment results demonstrated that the attenuated vaccine of fowl pox(FP) has sevious interference effect on the generation of hemagglutination inhibition (HI)antibody of Newcastle disease(ND)attenuated vaccine,When ND vaccine was innoculated with in 15 day after the innoculation of FP vaccine,it can be found that FP vaccine has interfereonce effects of different degrees to the generation of HI antibody of ND vaccine.The mean titer of ND antibody is 0.15～1.35(log 2 )lower than the group that using only ND vaccine.For chick innoculation,there is no significant difference in the mean value of ND antibody between innoculation using both FP and ND attenuated vaccines and that innoculating ND vaccine 15 day after FP attenuated vaccine (P0.05).The experiment results shown that the lower level of immune antibody and immune protection resulted from the irrational FP and ND immune procedure is one of the reasons that leading to ND immune failure.This has significant practical meaning to the control and protection of the epidemic atypical ND of immunzed chicken flock.