Trichothecenes, T-2, HT-2, Diacetoxyscirpenol (DAS) Mycotoxin Poisoning
Fusarium tricinctum and some strains of F. graminearurm, F. equiseti, F. sporotrichioides, F. poae, and F. lateritium produce T-2 and other toxic trichothecenes. These fungi commonly attack grains and can grow at temperatures from slightly above freezing to about 86 degrees F. T-2 and HT-2 toxins are produced over a temperature range of 46 degrees to 77 degrees F, with the maximum production at temperatures below 59 degrees F. This group of toxins was associated with ATA, which killed thousands of human beings in the USSR in 1913 and after World War II.
Apparently all domestic animals are susceptible to injury by dietary intake of T-2, HT-2, and diacetoxyscirpenol (DAS) in the range of a few ppm. In poultry, T-2 toxin in feed contaminated with 1 to 3.5 ppm of T-2 and 0.7 ppm of HT-2 (a closely related toxicant) may produce lesions at the edges of the beaks, abnormal feathering in chicks, a drastic and sudden drop in egg production, eggs with thin shells, reduced weight gains, and mortality. The same feed given to turkeys results in reduced growth, beak lesions, and less immunity to infection.
T-2 and DAS in cattle feed results in unthriftiness, decreased feed consumption, slow growth, lowered milk production, and sterility. An outbreak of the hemorrhagic bowel syndrome and death of some animals can occur in herds of cattle and swine.
In swine, infertility with some lesions in the uteri and ovaries result from consumption of feed contaminated with 1 to 2 ppm of T-2 toxin. When sound feed was provided to all domestic animals, the troubles quickly disappeared. T-2 toxin and DAS in amounts sufficient to cause to cause toxicoses have been found in corn still in the field, in silage, and in prepared feeds made in part from corn.
These toxins have also been identified in weather-delayed-harvest soybeans. Feed contaminated with these toxins must be handled carefully because these toxins can cause severe skin irritation. As with most other mycotoxins, the only control is to avoid contaminated feeds.
