Efficacy of live attenuated and inactivated oil emulsion infectious bursal disease virus vaccines in broiler chicks

This study was carried out with the aims to evaluate the efficacy of indigenous live and inactivated Infectious bursal disease virus (IBDV) vaccines in broilers. Two hundred and fifty (250), a-day-old broiler chicks divided into five groups (A-E) were immunized with live and inactivated vaccine at varying ages. Live vaccine was given to group A (at 8 days post hatch), B (at 8, 15 days post hatch), C (at 8, 15 and 23 days post hatch) and D (at 8 days post hatch). In addition group D received at booster dose of inactivated at 21 days of age, while group E served as control. Antibody titers were measured via Agar Gel Precipitation (AGP) test and ELISA, while the degree of protection against the virulent strains of IBDV was also recorded. Results showed that vaccine program adopted for group C and D produced significantly (P less than 0.05) higher antibody titer as compared to other groups. While a significant (P less than 0.05) difference in antibody titers was observed between group A and B while no considerable antibodies were detected in group E. The response to challenge dose was recorded as the difference of lesions in bursa, pectoral muscles or other visceral organs with the exception of group C and D. The study suggests that broiler chicks may be vaccinated at days 8, 15 and 23 with live attenuated vaccine or live attenuated vaccine followed by inactivated vaccine at days 8 and 21 that could provide an adequate protection against the virulent form of IBDV.