Chapter 82 - Ergot

Abstract

Ergot is a general term that applies to all species of the fungus Claviceps. Ergotism refers to the disease conditions associated with ingestion of toxic levels of ergot by animals and humans. This chapter primarily addresses alkaloids produced by Claviceps purpurea and the various toxic effects, called ergotism, which they produce in animals and humans. The source of exposure to animals includes ergot-infected grains in feeds such as barley, rye, wheat, and oats as well as infected seeds in forages consumed while grazing or in hay and silage. Clinical syndromes include gangrene of the extremities of cattle and horses, hyperthermia and production loss in cattle, agalactia, and abortion in swine, agalactia, and reproductive effects in mares. Clinical disease associated with Claviceps has a parallel in fescue grass toxicosis where gangrenous ergotism, hyperthermia, production loss in cattle, and adverse effects on reproduction and lactation in horses are similar. The seeds of fescue grass can be infected with C. purpurea, but the endophyte fungus Neotyphodium coenophialum produces the ergot alkaloids of fescue grass toxicosis. Ergot infection in cereal grains and grasses remains a concern for livestock and horses.