PRODUCTION OF THE ANTIGEN OF INFECTIOUS BURSAL DISEASE VIRUS (IBDV) FOR THE AGAR-GEL PRECIPITIN TEST AND ITS SENSITIVITY COMPARED TO THE VIRUS-NEUTRALIZATION TEST AND ELISA

An antigen for the agar-gel precipitin test (AGPT) was prepared from a n isolated strain of the infectious bursal disease Virus (IBDV). In th is paper the results obtained by comparative investigation of sera fro m one-day-old chickens and rearing chickens on the presence of antibod ies to IBDV by using the methods of AGP, virus-neutralization (VN) and enzyme-liked immunosorbent asaay (ELISA) were described. The geometri c mean value (GMV) of the reciprocal of the VN titers for the AGP-posi tive sera in group 1 was 638,30 and for the AGP-negative sera 50,80. i n group 2 (vaccinated chickens) the GMV of the reciprocal of the VN ti ters for the AGP-positive sera was 747,30, and for the AGP-negative se ra 68,57. In both chicken groups AGP-positive sera had a VN titer of 2 (7) or greater, with exception of one serum with the VN titer 2(5). In 95% of the investigated samples the AGP-positive sera had an antibody titer as determined by ELISA greater than 3. It could be concluded th at the obtained antigen is specific in determining precipitin for IBD virus. Because of the appearanceof false negative reactions, the antig en obtained for the AGPT can be recommended with some caution for esta blishing postvaccional or postinfec5ious antibody titers.