Tall Fescue Toxicosis

widely used forage crop. It is insect and nematode resistant, tolerates poor soil and climatic conditions well and has a long growing season. Unfortunately, tall fescue also has a downside. Most tall fescue in the state is infected with a fungal endophyte, Neotyphodium coenophialum (formerly called Acremonium coenophialum) that is toxic to animals. Tall fescue was brought to this country from Europe in the late 1800s. It was officially discovered in Kentucky in 1931, tested at the University of Kentucky and released in 1943 as “Kentucky 31.” It became popular with farmers in the midto late-1940s and 1950s, spreading quickly throughout the midwestern and southern United States. Today it is accounts for well over 40 million acres of pasture and forage land in this country. In Missouri alone, tall fescue covers approximately 17 million acres. Early producers of tall fescue were excited by the ease with which they could establish and maintain a stand. Soon, however, conflicting reports began circulating. For some reason animals were not performing well when allowed to graze tall fescue. Research into the causes of poor animal performance resulted in the discovery of a small fungus that grows between the cells. This fungus came to be known as the “endophyte” because it was “in” (endo) the “plant” (phyte). Followup research revealed that this endophyte could produce ergot-like alkaloids under certain conditions.