OCCURRENCE OF HEMAGGLUTINATION-INHIBITION ANTIBODIES AGAINST EGG-DROP-SYNDROME-1976 VIRUS IN BROILERS

From a total of 22 broiler flocks 347 serum samples were screened by t he haemagglutination inhibition (HI) test and 114 (32.9%) were positiv e for antibodies to egg drop syndrome 1976 (EDS'76). The HI titres of the serum samples ranged from 2 to 9 log(2) and the overall geometric mean titre was 3.9 log(2). Of the serum samples 82.5% showed HI titres between 2(2) to 2(5) and the most frequent titre was 2(3). All the fl ocks were positive and the flock prevalence of HI antibodies ranged fr om 13.3 to 46.6 per cent. The age distribution of HI antibodies and th eir titres have also been recorded. The widespread prevalence of EDS'7 6 virus infection in broilers and its likely significance are discusse d.