Mycotoxins occur sporadically both seasonally and geographically. The formation of mycotoxins in nature is considered a global problem. They occur naturally in a wide variety of feedstuffs used in livestock feeds only under aerobic condition. Fungi are extremely adaptable organisms being able to metabolize a large variety of substrates over a wide range of environmental conditions. Mycotoxins are a heterogeneous group of harmful secondary fungal metabolites. Most of these mytocoxins belong to the three genera of fungi: Aspergillus, Penicillium and Fusarium. Although over 300 mytocoxins are known, those of most concern based on their toxicity and occurrence, are aflatoxin, vomitoxin, ochratoxin, zearaleone, fumonisin and T-2 toxin. They are produced in cereal grains before, during and after harvest in various environmental conditions 1303453009.php