Abstract
A study was conducted to assess the effects of aflatoxin contaminated feed on the immunoresponse of one-day old layer chicks to attenuated live virus vaccines for Newcastle disease (ND), infectious bronchitis (IB) and infectious bursal disease (IBD). Concurrent exposure of chickens to 2tiO parts per billion (ppb) aflatoxin in feed and vaccination against ND, IB and IBD resulted in lack of adequate protection against subsequent experimental challenge, as assessed by antibody responses compared to chickens fed aflatoxin-free ration. The mortalities were higher in chickens fed 200 ppb of aflatoxin than in chickens fed on aflatoxin-free ration.