Comparison of the antibody response of Nigerian indigenous and exotic chickens to infectious bursal disease virus infection.
Twenty indigenous chickens and 40 Harco cockerels at four weeks of age were inoculated with 80 µl of IBD virus inoculum, equivalent to 2×103.5 chicken LD50, via conjunctival instillation. The IBD virus antibody response was determined by agar gel precipitation test (AGPT) and enzyme-linked immunosorbent assay (ELISA) for a period of eight weeks post infection (pi). Precipitin lines were observed from six weeks to eight weeks pi in the indigenous chickens while none was observed in the exotic chickens for the period of observation. On the other hand, ELISA detected the IBD virus antibody from five weeks to eight weeks pi in indigenous chickens, while it was detected between one week and eight weeks pi in the exotic chickens. Average ELISA unit (EU) values ranged from 0.15 to 50.3 peaking at six weeks pi in the indigenous chicken while it ranged from 3.7 to 13.0 peaking at three weeks pi in the exotic chickens. From this study, it could be concluded that antibody response to IBD virus infection in the indigenous chicken is slower but the level higher, than in the exotic chickens.