Evaluation of two vaccination programs to control infectious bursal disease in commercial broilers

ABSTRACT

An experimental study was carried out to compare protection induced by two infectious bursal disease [IBD] vaccination programs in commercial broilers. Chickens inoculated with live vaccine at 7 and 21 days old were protected against mortality but clinical signs of IBD were noted after challenge at 28 and 35 days old. Chickens inoculated with both live vaccine [at 7 and 21 days old] and inactivated vaccine [at 8 days old] were better protected against challenge at 28 and 35 days of age. This vaccination program protected challenged chickens against both mortality and clinical IBD signs. However, the bursa body weight ratios were lower than those of the control birds [P < 0.05]