Mycotoxicosis refers to the syndromes resulting from ingestion, skin contact or inhalation of mycotoxins. Mycotoxins are the secondary metabolites of molds belonging to several genera, in particular Aspergillus, Fusarium and Penicillium spp. Other genera include Alternaria, Chaetomium, Cladosporium, Claviceps, Diplodia, Myrothecium, Monascus, Phoma, Phomopsis, Pithomyces, Trichoderma and Stachybotrys. Studies show that mycotoxins contaminate 25% of the world's agricultural products each year. Agricultural products most affected include cereal grains (wheat, barley, millet, oats, peas, millet, corn), dried fruits, nuts, hay, pasture grasses and spices. Not all mycotoxins are toxic, however the major mycotoxins that adversely affect cattle include aflatoxin B1(AFB1), deoxynivalenol(DON), zearalenone (ZEA), and ochratoxin A (OTA).

Mycotoxin Name	Produced by	Description	Associated Syndrome
Aflatoxins	Aspergillus flavus, A. parasiticus, A. nomius and A. pseudotamarii.	Among the various toxic mycotoxins, AFB1 is the most lethal, exhibiting harmful hepatotoxic, mutagenic, teratogenic and carcinogenic effects on many species of animals.	Liver and kidney damage
Ochratoxin A (OTA)	Aspergillus ochraceus in warm climates) and Penicillium (predominately P. verrucosum found in temperate climates)	Found commonly in cereal crops; however oats and wheat, as well as their by-products such as bran and middlings, are at the highest risk of contamination.
Trichothecenes (T-2 toxin, diacetoxyscirpenol, neosolaniol, nivalenol, diacetylnivalenol, deoxynivalenol (DON), HT-2 toxin, and fusarenon X)	A common contaminate in corn and wheat and are responsible for causing digestive disorders, feed refusals, edema, dermatitis, oral lesions, hemorrhaging, and blood disorders.
Zearalenone (ZEA)	Fumonisin graminearum	Found most frequently in moldy hay, corn, and pelleted commercial feed. It causes problems with fertility and reproductive ability.

Mycotoxins can cause acute poisoning if a large amount are consumed in a short period of time, and chronic poisoning if small amounts are ingested over an extended period of time. The symptoms of mycotoxicosis depend not only on the type of mycotoxin, but also to the relative amount and duration of exposure as well as the species, age, sex, health, environment, nutritional state and particularly for the interactions with other toxic insults.