COMPARATIVE SERO-EVALUATION OF INFECTIOUS BURSAL DISEASE VIRUS VACCINE IN COMMERCIAL CHICKEN

Abstract

The level of antibody titer against infectious bursal disease (IBD) in commercial chickens was determined using comparative sero evaluation through indirect ELISA test method. One hundred chickens of 1 day old were collected from a commercial hatchery and they were divided into two treatment groups named as ‘treatment group’ (flock 1) and ‘control group’ (flock 2). Serum samples of the flocks were collected randomly four times on day 1, 8, 16 and day 28. Serum samples were examined to quantify antibody titer using indirect ELISA method. A variation in the antibody titer was observed among chickens of two different flocks. Mean antibody titers were found at of 8686.4 and 9304.07 in day old chickens of flock 1 and flock 2 respectively. The mean antibody titers 7732 and 6375.15 were found in 8 day chickens of flock 1 and flock 2 respectively. The mean antibody titers 726.25 and 727.5835 were found in 16 days old chickens of flock 1 and flock 2 respectively. These chickens of treatment group (flock 1) were vaccinated with Gumboro live vaccine on days 16 and 21 while chickens of flock 2 were kept without vaccination. Blood samples collected on day 28 from both vaccinated and nonvaccination flocks were subjected to ELISA. The average antibody titers 2520.75 was found in 28 days old chickens of flock 1 after vaccination but the average antibody titers 110 was found in nonvaccinated flock 2. The day old samples contained high level of antibody titer on average and the level gradually declined and persisted up to 15-20 days. On day 28, the level of antibody reached much above minimum protection level in vaccinated chickens but the level was much below the protection level in nonvaccinated chickens. The results suggest that chicks should be vaccinated at around day 14, when the antibody level reaches to nearly minimum protection level.