Articles on forages, animals, and grazing systems
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Extension Forage Specialist
University of Kentucky
Phone: (859) 257-3358
Fax: (859) 323-1952
Tall Fescue, a cool-season perennial grass, is the most predominant forage in the US covering over 36 million acres. It is extremely prevalent in areas of the southeastern United States because it possesses desirable characteristics including tolerance to drought, flooding, heavy grazing pressure, and a long growing season. However, tall fescue can have negative effects on livestock. The same fungal endophyte that grows in the plant and is responsible for tall fescue’s desirable characteristics is also responsible for producing ergot alkaloids, specifically ergovaline, that proves to be toxic to livestock causing tall fescue toxicosis.
Symptoms of tall fescue toxicosis include a rough hair coat, reduced feed intake and weight gain, decreased milk production, fertility issues, and elevated body temperature. Cattle can be seen spending more time in shade or water trying to cool off, and less time grazing. Poor animal gains and fertility issues have been estimated to cost the U.S. Beef industry between $600 million to over $1 billion annually.
Producers are looking for ways to decrease this economic loss and different varieties of tall fescue have become available. Endophyte-free tall fescue is one in which the fungal endophyte does not grow in the plant making it non-toxic, but this compromises the desirable plant characteristics of tall fescue. This can impact persistency, especially under grazing. There are also novel endophyte fescues, which carry the endophyte that enhances the persistence, but does not produce ergot alkaloids, making it safer for livestock to graze. Current research has shown that grazing novel endophyte tall fescue results in excellent performance, while showing no signs of tall fescue toxicity. In a two year study conducted at the University of Arkansas, it was shown that grazing a novel endophyte tall fescue instead of an endophyte infected variety led to higher calf weaning weights and cow pregnancy rates. Also, several studies on stocker gains have consistently shown that animals grazing novel endophyte tall fescue compared to a endophyte infected tall fescue have smoother hair coats, lower body temperatures, spend more time grazing, and result in significantly higher weight gains.
Several varieties of novel endophyte tall fescue have become available on the market. Many companies will carry one of the following varieties of novel endophyte tall fescue: Duramax Gold, Estancia with ArkShield, Jesup MaxQ, Texoma MaxQ2, and BarOptima Plus E34. For more information on novel endophyte tall fescue varieties, please refer to the University of Kentucky Forage Extension website, at www.uky.edu/Ag/Forage . The forage extension website not only has a large selection of publications but also electronic versions of variety test reports performed in Kentucky and surrounding states. The following publication includes the novel endophyte tall fescue variety tests for yield: http://www.ca.uky.edu/agc/pubs/PR/PR646/PR646.pdf. For variety trials conducted on grazing tolerance and preference, please refer to this publication: http://www.ca.uky.edu/agc/pubs/PR/PR651/PR651.pdf.
Planting novel endophyte tall fescue varieties has become increasingly more popular; it’s a great way to establish tall fescue into new pastures without the negative performance effects. However, novel endophyte tall fescue varieties are significantly more expensive than the popular Kentucky 31 tall fescue. Even though it is a higher initial cost, it may be more economical in the long run by increasing animal performance. Use best management practices when replacing an existing stand and recognize that it may be necessary to keep animals off fields for a period of time to allow seedlings to establish. With the time to remove an existing stand, seed a new variety, and manage establishment, your pasture could be unavailable for six or more months. It’s important to consider extra feed for animals during this time or decreasing herd size. This period of time may seem management intensive, but making improvements to animal performance will have positive long term returns.
While it is difficult and costly to renovate a pasture, the long term benefits may increase profitability by enhancing animal performance. When deciding which option is most fitting, consider the goals of the operation, existing field availability, costs of seed and labor, and long term benefits. Contact your local county extension agent to assist in deciding on a best management plan for your farm.