Effects of dietary aflatoxin and ammonia-inactivated aflatoxin on Newcastle disease antibody titers in layer-breeders.

Corn containing aflatoxin and the same corn ammoniated to inactivate aflatoxin was incorporated into layer diets to supply 500 ppb and 2.3 ppb aflatoxin, respectively, to determine whether such diets interfere with immunity to Newcastle disease vaccination. Control diets containing uncontaminated corn, both with and without ammoniation, were also fed. A trial 3 months long with 12 birds per treatment was conducted. Vaccination treatments included no vaccination, a single vaccination at the initiation of each trial, and monthly vaccinations for three months. Serum samples, for determination of Newcastle disease hemagglutination-inhibition titers by the microtiter method, were collected just before vaccination and seven days postvaccination, as well as at trial termination. Birds receiving a single initial vaccination and fed a diet containing 500 ppb aflatoxin showed a significant (P less than 0.05) decrease in HI titers, whereas birds similarly vaccinated and fed a diet containing inactivated (ammoniated) aflatoxin showed no reduction in titers regardless of dietary treatment.