Fescue toxicosis is commonly seen in cattle grazing endophyte-infected tall fescue. Most often associated with spring and early summer grazing, tall fescue toxicosis is a threat in the fall, especially to new bulls and cattle grazing pastures to the ground. Heather Smith Thomas shares many considerations when dealing with tall fescue to reduce the incidence of toxicosis in this article.
In most unimproved pastures, tall fescue is infected with the fungal endophyte Epichloë coenophiala that is good for the plant but toxic to cattle <Link>. Of the alkaloids produced by the endophyte, ergovaline is the predominant ergot alkaloid mycotoxin that significantly impacts livestock health and productivity, as shown in the post image.
Source: Progressive Forage, September 15, 2025. Link.
INSIGHTS: The guidance on late cutting hay and converting fescue pastures is worth discussing with producers as part of a herd improvement conversation.
Image: Link.