Mycotoxins in fungal contaminated samples of animal feed from western Canada, 1982-1994

Feed samples from 94 cases involving fungal contamination and suspected mycotoxicosis of farm animals in western Canada were examined during 1982-1994 to assess the incidence of mycotoxins. Samples were analyzed for aflatoxins, ochratoxin A, citrinin, sterigmatocystin, and the fungal estrogen zearalenone. Samples infected with Fusarium fungi were additionally assayed for nivalenol, deoxynivalenol, fusarenone-x, 15-acetyl-deoxynivalenol, diacetoxyscirpenol, HT-2 toxin, and T-2 toxin. Mycotoxins were found in 21 feed samples from 17 cases (18% of the reported cases), generally at levels far below those needed to induce symptoms under laboratory conditions. HT-2 toxin and other type-A trichothecenes were detected in 5 samples, deoxynivalenol and other type-B trichothecenes in 13, ochratoxin A in 5, and citrinin in 2. In 9 cases, symptoms observed in the animals were consistent with the known effects of the mycotoxin(s) found in the particular feed samples.