On-farm investigation to determine the appropriate age to vaccinate chicks with the Nigerian infectious bursal disease vaccine (fibrogumbovacReg.).

摘要

This study was conducted to determine the appropriate age to vaccinate chicks with locally manufactured infectious bursal disease vaccine (fibrogumbovacReg.) as part of our efforts to address the problem of vaccine failures against Gumboro disease. 90 cockerels, 1-day-old, were divided into three groups: A, B and C with group C subdivided into C1 and C2. Birds in group A were vaccinated with the fibrogumbovacReg. IBD vaccine at 10 and 18 days old, while birds in group B were vaccinated with 14 and 35 days old. Birds in groups C1 and C2 were not given any IBD vaccine. All groups, except subgroup C2, were challenged with 20% (w/v) suspension of bursa of Fabrius confirmed to be naturally infected with IBD virus after vaccination. All the vaccinated birds sero-converted using the agar gel precipitating test (AGPT). The result also indicated that administration of the IBD vaccine at 10 and 18 days old had better protection against IBD based on the observed difference in the morbidity and mortality between the vaccinated and unvaccinated IBD challenged birds. However, there was no significant difference (P>0.05) in the potency of the vaccination regimes. It is suggested that chicks should be vaccinated at 10 and 18 days old when NVRI fibrogumbovacReg. vaccine is used.