In this article, I’m going to be talking about fescue and its use in pastures. Fescue is a very commonly grown pasture grass around here. It is a cool season grass, which means that it does best in the spring and fall. Hot, dry summers are difficult for fescue and will stress it out. Fescue can be an excellent source of forage for livestock. Unfortunately, fescue also has a dark side to it that creates problems for livestock that graze it. I’d like to talk about what causes those problems, and things that you can do to mitigate them in the pasture.
An endophyte can grow in fescue. An endophyte is a fungus that lives inside a plant. If livestock consume too much of the endophyte they’ll get what’s called fescue toxicosis. Symptoms of livestock that have fescue toxicosis are reduced conception rates, decreased weight gain, decreased milk production, constricted blood flow to extremities, elevated body temperature, heat intolerance, excessive nervousness, and failure to shed winter coats in the spring. Generally, fescue toxicosis doesn’t kill livestock directly, but it will weaken them and leave them in an unhealthy state. In horses, the worst effects of fescue toxicosis are in pregnant mares, because they are very sensitive to it and it can cause late term abortions, or thickened placentas. Even very low levels of endophyte can cause fescue toxicosis in equine.
The endophyte does not spread by infecting nearby uninfected fescue plants. It spreads because the endophyte actually benefits the plant by making it more drought tolerant and more persistent under grazing. Therefore, if you have planted fescue that is endophyte free, after a few years you can expect your pasture to be full of endophyte-infected plants, because the endophyte makes the fescue more resilient. Because of this, I would say that it’s safe to assume a pasture is endophyte infected, unless you know that you have planted either endophyte free or novel type endophyte recently.
Novel endophyte means that the fescue still has an endophyte in it, but with the bad parts of it taken out. Fescue with novel type endophyte in it that UGA Extension recommends are MaxQ and Texoma MaxQ II. The novel endophyte will have the increased drought tolerance and grazing tolerance, but not make livestock sick.
Another option that many producers use is mixing fescue stands with orchardgrass. Orchardgrass is a very good quality forage that is also a cool season grass. Mixing stands means that livestock will consume less of the endophyte so they will be healthier. An issue with this is that fescue is more persistent than orchardgrass under grazing conditions. It will usually thin after 2-3 years and need renovation. Orchardgrass is best established on a prepared seedbed. The varieties of orchardgrass that UGA Extension recommends are Olympia and Benchmark Plus.
Another strategy is to dilute fescue stands with legumes. Clover provides excellent forage quality, so it is able to balance out negative effects from fescue endophyte. White clover is a perennial that can be used. The UGA Extension recommended varieties are Durana, Patriot, and Renovation.
UGA does not test plants to see if the endophyte is present. You can send samples to the labs at The University of Tennessee for testing. However, as I said before, unless you know that you have recently planted novel type endophyte fescue, my money would be on it being infected.
If you have more questions about fescue toxicosis go to georgiaforages.caes.uga.edu, contact your county Extension office, or email me at Jacob.Williams@uga.edu.