Fescue hay is a common perennial grass forage used widely for livestock, especially throughout the temperate regions of the United States known as the “Fescue Belt.” Derived from Tall Fescue (Schedonorus arundinaceus), it is prized by producers for its hardiness and resilience. As a cool-season grass, it maintains persistence under various environmental stresses, including drought and heavy grazing pressure. Its deep root system allows it to produce high yields and provide a consistent feed source for cattle and other livestock.
Identification and Nutritional Profile
Tall fescue is a bunch-type cool-season grass popular for hay production due to its consistent yield. When harvested, it has long, coarse leaves and stems. Nutritional quality depends heavily on maturity; producers aim to cut it at the boot stage, before seed heads emerge, to maximize value.
Fescue hay is a moderate-quality feed, typically suitable for maintaining adult livestock rather than supporting high production needs. It generally contains 8% to 14% crude protein (CP) and 50% to 60% total digestible nutrients (TDN). This moderate content is sufficient for the maintenance requirements of mature beef cattle, especially as a winter feed source. Compared to higher-quality forages like alfalfa, fescue is generally ranked as a utility feed.
The Endophyte Connection and Fescue Toxicity
The safety of fescue hay is profoundly impacted by the presence of Epichloë coenophiala, a symbiotic fungus (endophyte) living entirely within the plant tissue. The endophyte provides tall fescue with beneficial traits like drought tolerance and persistence.
However, it also produces toxic chemical compounds called ergot alkaloids; ergovaline is the primary concern. Ergovaline is a potent vasoconstrictor, narrowing blood vessels and reducing blood flow to the extremities. This affects the body’s ability to regulate temperature, leading to fescue toxicosis. Symptoms vary by temperature and species but are grouped into two major syndromes.
In warm weather, cattle consuming infected hay may develop “summer slump,” characterized by hyperthermia, reduced feed intake, poor weight gain, or poor milk production. These animals often exhibit a rough hair coat and seek shade due to impaired heat dissipation. Conversely, in cold weather, reduced blood flow can lead to “fescue foot,” which progresses to dry gangrene in the tail, ears, and feet, sometimes causing the sloughing of hooves. Horses are particularly sensitive, experiencing reproductive issues like prolonged gestation, thickened placentas, and foaling difficulties. Toxicosis signs typically appear when ergovaline levels in the diet reach 200 to 800 parts per billion (ppb).
Managing Fescue Hay for Livestock
Livestock owners must implement specific management protocols to utilize endophyte-infected fescue hay safely. The most reliable method for determining the safety of any fescue hay is to submit a sample to a laboratory for ergot alkaloid testing. Testing provides a specific ergovaline concentration, allowing informed feeding decisions; levels above 400 ppb are generally considered a threshold for potential toxicosis in cattle. If testing reveals high alkaloid levels, the hay can be diluted by blending it with non-toxic forages, such as alfalfa, clover, or other grass hays. Dilution reduces the total concentration of ergot alkaloids consumed, mitigating toxicosis symptoms. While blending is useful, animal performance must be carefully monitored as it may not completely eliminate negative effects.
A long-term solution involves transitioning to tall fescue varieties containing a “novel endophyte.” Unlike the wild-type endophyte, these engineered varieties are non-toxic, providing the plant with the same benefits of hardiness and persistence without producing harmful ergot alkaloids. Novel endophyte varieties are a preferred choice for establishing new stands, offering agronomic advantages while ensuring animal safety and maximizing performance. Endophyte-free varieties are also available, but they often lack the superior hardiness needed for persistence in difficult environments.