There are several types of mycotoxins (toxins produced by the fungi) e.g. aflatoxin, ochratoxin etc. Many species of fungi produce them but Aspergillus flavus is the main contributor. Peanut meal, corn meal, cottonseed meal cake, many grains allow the fungus to grow rapidly if the moisture content and storage temperature is favourable. Mostly food grains rejected for human consumption due to fungal infestation are used in poultry feed that becomes mycotoxin-laden feed. These mycotoxins are not destroyed easily by heat, chemical treatments or prolonged storage. Moreover, after consumption by poultry, they are deposited in liver and go on getting accumulated. The consumption of such birds by human population results in ingestion of intoxicated meat.
Symptoms and lesions: Young birds appear to be more susceptible than adult birds.
Mortality depends upon the quantity and duration of consumption of toxicated feed by the host. Initially, they show lethargy, loss of appetite, impaired growth, ruffled feathers and drooping wings. Higher level of toxicity results in ataxia, opisthotonus and convulsions. Low doses do not cause death of a bird but are responsible for several ill-effects including impaired growth and intermittent secondary infections and immunosuppression. Ducks rank higher on mycotoxin sensitivity than poultry. Initially liver becomes swollen and discolored in appearance but later becomes cirrhotic and nodular. Ascites, hydropericardium and catarrhal enteritis are frequently present. Aflatoxin is carcinogenic; tumors usually develop in the liver.
Diagnosis: It is generally based upon history and lesions. Analysis of affected feed will confirm the diagnosis.
Prevention and control: Proper storage of feed in a cool dry place, avoiding long storing and dampness, replacement/ frequent raking of wet litter and use of toxin binders in feed are the standard methods.