Determination of the serum antibody level of different age groups of broiler breeder against Infectious Bursal Disease (IBD) vaccine

Abstract

A study on Infectious Bursal Disease (IBD) was conducted on broiler breeder of strain Cobb500 at Thakurgaon district of Bangladesh. The study was conducted on day old chicks and postvaccinated flocks (up to 75 wks) to measure the antibody titer by indirect ELISA method (Biochek, ELISA kit). Five flocks (45,000 birds) of a specific farm at thakurgaon from day old chicks to 75 wks (just before culling) with a history of vaccination were included in this study. Maternal derived antibody (MDA) mean titer of day old chicks were found mean titer range 3395 to 5184 and vaccination prediction date was 14" to 16" day after hatch respectively. Vaccination Date Prediction was applied with the “Deventer Method” predicting for a intermediate plus vaccine to vaccinate at 14 D of Age (Optimal Titer To Vaccinate = 500, Half-life MAB = 4.5 days and Vaccination Cover = 75%). Then blood serum samples (N=92 per flock) were tested by indirect ELISA at age 14th day, Swks, 8 wks, 23 wks, 50 wks & 75 wks of each vaccinated flock At age 14th day the mean titer level was around 500 which supported “Deventer Method” of vaccination date prediction. At different age groups (growing, laying & mid laying) protective mean titer level were found & mean titer is declined at last stage of laying (just before culling) but the titer level were enough to produce high MDA for their offspring.