Mycotoxins in Animal Feeds and Prevention Strategies: A Review*

摘要

Mycotoxins are secondary metabolites produced by moulds, mostly belonging to the three genera Aspergillus, Penicillium and Fusarium. They are produced in cereal grains as well as forages before, during and after harvest, in various environmental conditions. Mycotoxins generally display great chemical heterogeneity and approximately 400 of these fungal metabolites are considered to be toxic. Mycotoxin metabolism is complex and involves pathways of bioactivation and detoxification in both humans and animals. Detoxification occurs via biotransformation mediated by enzymes in the host cells and in the digestive microbial flora. Some of the toxins or their metabolites may become fixed in animal or human tissues. However, most are eliminated in the urine,faeces and milk. In animals, toxicity is generally revealed as chronic minor troubles and only rarely causes death. The presence of mycotoxins in feeds may decrease feed intake and affect animal performance, hi addition, the possible presence of toxic residues in edible animal products (milk, meat, offal), may have some detrimental effects on human health. Maximum acceptable doses in feeds and milk have been set for certain mycotoxins by international authorities. The potential risks of mycotoxins maybe controlled by checking plant material for fungal contamination, by improving methods of cultivation, harvest and storage, by eliminating or diluting toxins from the contaminated food or feeds and by using adsorbents to reduce the bioavailability of toxins in the digestive tracts of animals.