Effects of long-term feeding of ammoniated, aflatoxin-contaminated corn to Fischer 344 rats.

The effectiveness of ammonia treatment in reducing the chronic toxicity of aflatoxin-contaminated corn was determined. Fischer 344 rats were fed semi-purified rations containing 20% w/w corn that was either free of aflatoxin or naturally contaminated with 880 micrograms/kg total aflatoxin and was either treated with ammonia gas or was not treated. Therefore the rats that were fed the aflatoxin-contaminated diet received 176 ppb total aflatoxins. Body weight and food consumption were recorded throughout the study; hematological measurements were made after 87 weeks of feeding; and after 91 weeks the rats were killed and histopathological abnormalities were noted. Signs of chronic toxicosis in rats fed aflatoxin-contaminated corn included increased mortality, decreased hematocrit and hemoglobin levels, elevated serum alkaline phosphatase activities, and a 100% incidence of liver neoplasia. These signs did not occur in rats in the other dietary treatment groups, including those fed ammoniated, aflatoxin-contaminated corn. The results provide further evidence that the atmospheric ammoniation process effectively reduces the toxicity of aflatoxin-contaminated corn.