Mycotoxins are secondary chemical metabolites of different fungi. The most important mycotoxigenic fungi are from the genera: Aspergillus, Penicilli-um, Fusarium, Claviceps and Alternaria. Fusarium fungi are the most wide-spread in cereal-growing areas of the planet. Fumonisins, trichothecenes and zearalenone are the most commonly occurring Fusarium mycotoxins in cereal grains and animal feed. The occurrence of toxic metabolites in food, as well as in feed, represents a serious global problem for human health due to their toxic effects. Zearalenone is mainly produced by Fusarium graminearum and F. culmorum. Corn is the most frequently contaminated plant due to its distribution throughout the world. Contaminated products can lead to huge economic losses and pose risks to animals and humans. It affects animal health and mainly has estrogenic effects on various organisms. Swine are the most commonly affected domestic animals, but cattle and poultry may also be affected.