Fescue Toxicosis

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Late winter is not a time that we typically think of fescue toxicosis, as our thoughts are more like keeping animals fed and waging war on mud. However, I receive many calls from producers in late spring and early summer regarding many symptoms of this toxicity.

Fescue is a tough forage that handles trampling and drought and hot weather much better than many of its counterparts and we as livestock producers rely on it to produce most of our forage needs. But, this hardiness is made possible by a fungus that exists between the cell walls of KY 31 fescue plants and protects the plant from many climactic conditions. This endophyte (fungus) attributes greatly to summer slump in beef herds. Symptoms range from rough haircoats and poor shedding, to elevated body temps and sloughing of the tail switch and hooves. These animals often stand in water or under shade and pant profusely. The main thing is they are not grazing and filling up that rumen, and converting forage intake efficiently. The greatest problems from fescue toxicosis occurs in the summer months and into early fall. Toxin levels are at their greatest when seed heads are present with high concentrations in the seeds. Calves grazing toxic fescue show reduced weight gains on this reduced quality forage and milk production of their dams is lower.

In managing pastures to counter the effects of fescue toxicosis producers do have some tools to lessen the effects. Grazing pastures heavily or clipping to remove seed heads is a big help. This removes the toxin-laden seeds and starts the plants back growing. Try to get grass clipped while still in the boot stage or just before the flower emerges from the sheath for optimum results. In addition, producers should provide an abundant source of clean, fresh water and graze pastures with adequate shade during the hottest months of the year, as this is the time when animals will suffer most from an elevated body temperature and they need some relief.

Finally, maintaining around 30% clover in these infected fescue pastures can dilute the effects of the endophyte fungus. This can also apply to hayfields, as they are a big part of the forage production system. The extra nutrition from the clover can help along with these other management practices to minimize the effects of fescue toxicity in your herd.