Have you looked in your pastures lately? A good portion of pastures in our area are made up of tall fescue (and most likely the endophyte infected version). While this variety of fescue has many benefits, such as a hardy nature and long growing season, it also has a downside. As new beef producers who have invested a lot of money in our herd, we were quite alarmed when several of our cows started losing the ends of their tails last summer. We had heard of fescue foot and other problems related to endophyte infected varieties of tall fescue (E+ tall fescue), but hadn’t experienced it ourselves until then. Spring and summer are quickly approaching, and this year I wanted to be more prepared and learn how to best care for our animals and reduce the negative effects of the E+ tall fescue they are grazing.
What’s the big deal with E+ tall fescue? Missouri State Extension offers a lot of educational resources on this topic. The endophyte infected variety of tall fescue has a fungus that grows within the cell walls of the plant. In certain conditions, this fungus produces a toxin that can negatively affect your livestock. Problems that can arise from livestock grazing this type of fescue include losing weight, difficulty getting pregnant, losing offspring, heat intolerance, and it can cause constricted blood vessels, which is how animals end up with “fescue foot.” Due to reduced blood flow, the tissues in the affected area die. However, there are several ways to help offset the negative effects of E+ tall fescue. Some include: replacement, rotation, dilution, supplementation, fertilization, and close grazing.
Replacing E+ tall fescue can be costly and require a lot of time. However, several studies have shown it to be overall a cost effective option. If this is the desired route, the recommendation is to spray the field with an herbicide, seed a smother crop, and then respray with the herbicide. If your new desired grass is a spring seedling, the smother crop should be a winter annual grain such as wheat. If the new grass is a fall seedling, the smother crop should be a summer annual such as sudangrass.
Rotating your livestock in an intentional way can also help manage E+ tall fescue. Because hot temperatures can intensify the toxic effect, it helps to move livestock to a pasture that isn’t as heavily populated with the E+ tall fescue during this time. Studies done in Missouri have indicated that 88 degrees Fahrenheit may be the threshold for moving livestock off pastures that contain a lot of E+ tall fescue. They also specified that the cattle should remain off the E+ tall fescue for the rest of the summer in order to avoid negative effects such as inadequate weight gain.
Another way to reduce the toxic effects is to dilute the E+ tall fescue with another plant such as legumes including: red clover, white clover, annual lespedeza, alfalfa, and birdsfoot trefoil. Legumes are a great choice for diluting the tall fescue because these plants should not receive high amounts of nitrogen when fertilizing. This works well with E+ tall fescue because studies show that high amounts of nitrogen can worsen its toxicity. Supplementation with another feed, such as corn, can also help dilute the amount of E+ tall fescue that your livestock are taking in.
Lastly, because the highest amount of toxicity is located in the seed heads, close grazing can help mitigate the negative effects of E+ tall fescue. This can be achieved by having enough cattle to keep up with the amount of pasture they are on so that seed heads are not given the chance to develop.
Our approach will include several of these suggestions, including rotating our cattle to a smaller area of land so that they can keep up with the growth and prevent seed heads from developing, as well as using the other area that isn’t grazed during summer as a possible stockpile for fall and winter grazing. We will also give supplemental feed. Additionally, we recently learned about a mineral that contains capsaicin, which helps to open up blood vessels (opposite of what the toxin does). Vitaferm Heat is the name of this mineral, and there may be others. There are also ingredients (such as seaweed) that can be added to your feed that help open up blood vessels, so talk with your local co-op if you think this would be helpful in your operation. Always consult with your vet and local extension office before making land and herd management decisions.