Toxicity of field samples and Fusarium moniliforme from feed associated with equine-leucoencephalomalacia.

Feed samples of corn, pelleted feed, and oats associated with equine leucoencephalomalacia (ELEM) were obtained from North Carolina, Illinois, Indiana, and Oklahoma. These samples contained a high colony density of Fusarium moniliforme Sheldon which ranged from 64 to 87% of the total fungi. Fifty-nine F. moniliforme strains were isolated. Isolates of F. moniliforme in feed samples from Illinois, Indiana, and Oklahoma were cultured on corn. The fermented corn, mixed with regular feed and fed to one-day-old ducklings, effected a high mortality coefficient (average 55%). Methanol extracts of corn fermented with each of 14 representative F. moniliforme isolates from North Carolina feed were toxic to mice and some caused rabbit skin necrosis. Vomitoxin (deoxynivalenol), T-2 toxin, zearalenone, and moniliformin were not detected in feed samples or fermented corn. However, 4 to 10 ng of aflatoxin B1 per gram of feed was present in the four North Carolina samples. Bikaverin (C20H14O8), a characteristic red pigment of Fusarium sp., was found in the North Carolina feed samples. This is the first report of bikaverin in feed samples associated with ELEM.