MYCOTOXINS AS A POSSIBLE CAUSE OF FESCUE TOXICITY

Sporadic outbreaks of fescue foot occur in cattle grazing toxic pastures of tall fescue. The clinical signs of fescue foot can be produced by giving cattle extracts of the toxic hay. An alkaloidal fraction containing the major alkaloid festucine, prepared from such an extract, was not toxic to cattle. The sporadic and seasonal occurrence of fescue toxicity suggests a fungal involvement. One mold isolated from toxic fescue, Fusarium tricinctum, produces three toxins: 4-acetamido-4-hydroxy-2-butenoic acid-γ-lactone, 8α-(3-methylbutyryloxy)-4β, 15-diacetoxyscirp-9-en-3α-ol, and an unknown. Of 200 fungal isolates from toxic fescue or from nearby pastures (controls), almost all the toxin-producing molds belong to the genus Fusarium. The specific relationship, if any, of Fusarium toxins to fescue foot remains to be determined by tests in cattle. © 1969, American Chemical Society. All rights reserved.