Interference of infectious bursal disease virus on antibody production against Newcastle disease and infectious bronchitis virus

This work has the objective of verifying the interference of infectious bursal disease virus in the antibody production against Newcastle disease virus and infectious bronchitis virus. The experiment was carried out with 640 day-old-chicks from a 42 weeks old hen flock. The birds were separated into eight experimental groups (n=80/group) and were submitted to different combinations of vaccinations, with live vaccines, to Newcastle disease, avian infectious bronchitis, and infectious bursal disease with diverse combinations of days of vaccination. We verified that the utilization of polyvalent vaccinal programs have a different efficacy comparing to monovalent vaccinations when Newcastle disease, infectious bronchitis, and infectious bursal disease vaccinations are applied. This way, the use of vaccinations to infectious bursal disease in polyvalent vaccinal programs is desirable due to improvement of NDV response with the presence of IBV by the probable reduction of interference of IBV under NDV.