Tall Fescue Toxicosis and Management

Tall fescue toxicosis is one of the most costly animal disorders facing livestock producers in the eastern U.S. As reported by Georgia researchers in 1977, it is caused by a fungal endophyte. At present, there is no cure for tall fescue toxicosis. There are, however, proven management strategies that can lessen the effect of toxicosis. One strategy is the replacement of toxic tall fescue with cultivars that are endophyte‐free or contain beneficial endophytes. Other strategies involve management of toxic tall fescue pastures by interseeding other forages that can dilute the toxins, rotating livestock to non‐toxic pastures, supplementing the diet, limiting the rate of nitrogen fertilizer, controlling the seedheads, ammoniating the hay, and in the case of horses, administering medicinal treatments. Nearly all of these management practices are designed to limit the amount of toxin that is ingested in the animal. This guide will discuss the science and application of these management practices.