Fescue Foot Research Articles

Survey of Tall-Fescue Pasture: Correlation of Toxicity of Fusarium Isolates to Known Toxins

Several aspects of fescue foot in cattle suggest that this disease is caused by fungi growing on fescue grass. Certain fungi isolated from winter pasture yield toxins when grown on synthetic medium. Most of these toxin producers belong to the genus Fusarium. All but 1 of the 21 toxic and 7 questionably toxic Fusarium isolates produce either 4-acetamido-4-hydroxy-2-butenoic acid gamma-lactone, or 4beta, 15-diacetoxy-8alpha-(3-methylbutyryloxy)-12, 13-epoxytrichothec-9-en-3alpha-ol, or both.

The cytotoxicity of some transformation products of diacetoxyscirpenol

The cytotoxicity of eighteen relatives and transformation products of diacetoxyscirpenol, an important mycotoxin from Fusarium sp. implicated in mouldy corn toxicosis and fescue foot disease of cattle, has been investigated. The results are consistent with the hypothesis that toxicity is associated with the presence of the 12, 13-epoxytrichothecane nucleus, but other molecular features contribute to the manifestation of high toxicity. A method for the detoxication of diacetoxyscirpenol follows from the observation that non-toxic products result from the acid-catalysed re-arrangement of the 12, 13-epoxytrichothec-9-ene nucleus to the 10 → 13-cyclotrichothecane or apotrichothec-9-ene systems.

Toxic fungi isolated from tall fescue.

Extracts of cold-grown common molds isolated from tall fescue forage produce toxic effects on rabbit skin and hemorrhagic death in mice. A mixture ofCladosporium cladosporioides andFusarium nivale produced ruminal atony in a sheep. The clinical findings in the sheep show some similarity to those of cattle on toxic fescue pastures. Further work to determine the role of fungal toxins in the etiology of fescue foot in cattle is underway.

Identifying the toxic factor in tall fescue grass

Abstract A rapid and convenient bioassay method which may measure the toxic factor in tall fescue plants is described. Subcutaneous injections of tall fescue extracts were found to be physiologically active in mice. It is suggested that the response, which was measured as a reduction in deep body temperature, may be due to the unknown toxic factor which causes “fescue foot” in cattle. The relative potency of fescue hay was determined in terms of Prepared Ergot, and the equivalent activity was calculated to be 13.84 mg Ergotoxine/l00 g of oven-dried fescue.

Toxicity of tall fescue forage: A review

Tall fescue is grown in many parts of the United States as a forage crop and as a general purpose turf grass for airfields, highway berms, home lawns and athletic fields. It is a valuable forage grass, particularly in the southern and western areas of the countrv. Millions of acres of fescue are planted in the Southeast alone. Its popularity rests on its desirable agronomic features: it does well on poor soil, produces a dense turf which withstands grazing anid remains greer throughout much of the winter. Cattle grazing on fescue pasture are soimietimes affected with "fescue foot," a noninfectious disease of cattle characterized by lameness of the hind quarters and by a predisposition to dry gangrene of the extremities. The ineidence of fescue foot varies widely. In many cases, no syimptoms develop when cattle are on fescue pasture. In other cases, the outbreak may affect only a few of the cattle (31), or it imiay affect up to 78% of the herd (12). Although the symnptoms are similar to ergot poisoning, ergot is not involved in fescue foot. The exact cause of the disease is not known.