Mycotoxins are toxic metabolic byproducts of fungal growth on grains. There are over 100 known mycotoxins. High moisture content of grains can lead to fungal growth and toxin production. Fungi can produce toxins before or after grain harvest. Drought and insect damage to grain can increase the susceptibility of grain to fungal growth.
Occurrence: Worldwide. More common in warm wet climates.
Species affected: Ducks, turkeys, broilers, pullets, commercial layers, and broiler breeders are affected in decreasing order of susceptibility.
Age affected: All, but young are most susceptible.
Causes: Consumption of grans containing fungal producing toxins.
Effects: Signs include sleepiness, depression, paleness, and reduced egg production, fertility, and hatchability, depressed growth, feed conversion, and increased bruising and downgrading, and immunosuppression can occur.



Consumption of feed containing grains which contain toxins causes the disease. Mycotoxins
include aflatoxin produce by Aspergillus sp., trichothecenes toxins (T‑2, diacetoxyscirphenol (DAS) and deoxynivalenal (DON or Vomitoxin) can be produced by Fusarium sp. and ochratoxin produced Aspergillus ochraceous or Penicillin viridicatum.                 

Mode of transmission

Consumption of high moisture grains containing toxin produced by fungi.

Clinical signs

Signs include sleepiness, depression, paleness, and reduced egg production, fertility, and hatchability. Depressed growth, feed conversion and increased bruising and downgrading can occur.Mycotoxin

Postmortem lesions

Lesions associated with aflatoxin include scattered hemorrhage in the muscles, skin and intestinal tract, fluid around the heart, enlarged pale kidneys, and pale, enlarged fatty livers with hemorrhage and anemia. Lesions associated with trichothecenes include an inflamed GI tract, atrophy of bursa and thymus, necrosis of gizzard and proventriculus, dermatitis on the toes, pale or yellow bone marrow, yellow hemorrhagic liver, gout, and pus like lesions in the oral cavity. Lesions associated with ochratoxin include fatty liver with hemorrhage, enlarged pale kidneys with urates, heart necrosis, and urate deposits on the liver, spleen, and pericardium can be seen.


The clinical history, and gross and microscopic lesions are important. ELISA kits and column chromatography.


Mold inhibitors and toxin binders in the feed.

Find everything you need to know about mycotoxins on the All About Feed website.