Improved performance of progeny of broiler parent chickens vaccinated with infectious bursal disease oil-emulsion vaccine

Abstract

Field trials were conducted on nine broiler chicken flocks, which were the progeny of parents vaccinated with inactivated infectious bursal disease (IBD) oil-emulsion vaccine (OEV). The average increase in overall weight gains was 7.97% of weight gains of similar birds from live-vaccinated parents. Food-conversion ratios (FCR) were calculated for five of the trials. The average improvement in FCR over that of the control chickens was 2.89%. Every broiler flock contracted subclinical IBD, but there was no significant difference in overall mortality rates, except in one trial. In that trial, inclusion body hepatitis and Escherichia coli septicemia in the progeny of the parents that received only live vaccines caused increased mortality. Weekly monitoring of IBD antibodies in two of the trials showed that, in one trial, maternally derived antibody (MDA) persisted in the test chicks until at least 22 days of age and in the controls until at least day 15. In the other trial, MDA persisted until at least day 15 and day 8, respectively, in the test and control flocks. Field IBD challenge occurred at about day 30 and day 37 in the control and test chicks, respectively, in one trial and on day 17 and day 30 in the other. Overall weight gains and FCRs were not related to stocking densities.