Immunization of Chickens for the Control of Infectious Bursal Disease

Abstract

Six experiments were conducted involving 790 chickens inoculated with IBD (infectious bursal disease) vaccine produced at this station to determine a suitable age and route of vaccination. Vaccinated birds resisted a challenge dose that caused 10–20% mortality among unvaccinated challenged controls; whereas, there were no deaths among vaccinates. A total of 3,092,864 chicks in 135 flocks on 88 farms in Alabama and Mississippi were vaccinated at an average age of 5 days via the drinking water or intraocularly in initial trials. Mortality following vaccination averaged <0.78% during the reaction period (5 to 7 days) compared with an average 5% mortality in natural outbreaks on the same farms. There were no relapses or natural outbreaks in any of the 135 vaccinated flocks.