Manage tall fescue to control toxicosis effects.

Ames-Iowa livestock producers should add another entry to this week’s “to do” list: Check pasture for tall fescue.

“Many producers successfully manage pastures containing fescue, using some general  ‘good management practices” says Steve Barnhart, Iowa State University Extension forage specialist. “Producers can begin monitoring pastures now so they can start management as soon as fescue is identified,” he says in a news release.

Tall fescue is a winter-hardy cool-season grass productive April to October, he says. It also has many of the traits producers want in a pasture grass.

However, much of Iowa’s tall fescue harbors a fungus that resides in the grass plant as an endophyte. These endophytes contain alkaloids that can cause physiological and production problems-fescue toxicosis syndrome- in grazing animals.

In hot weather, large animals can overheat, adversely affecting daily forage intake, rates of gain, milk yield and reproduction. Symptoms include rough hair coats, limited mid-day grazing and frequent standing in streams or ponds.

In Cold weather, Poor circulation can cause lost ear tips, tails, lameness, and, in extreme situations hooves. Horses may even suffer abortions.

“Tall Fescue Plants can be identified by closely inspecting the pasture,” Barnhart Explained.

“Upper surfaces of the leaf blades have deep grooves from base to tip, the bottom surface is smooth and shiny. The edges of the leaf blades are serrated-finely saw-toothed from tip to base.”

“Seed stems, seed heads and lower stem bases, contain the highest concentrations of alkaloids; the green leaf blades the least,” Barnhart said

Management that minimizes animal access to seed stems and maximizes grazing of leaf blades goes a long way to lessening the undesirable effects of fescue in pastures. Management for stands with 50 percent or less tall fescue should start with clipping seed stems in May and June to keeping it in the leafy, vegetative condition.

Seed heads generally do not develop for the remainder of the year.

Avoid high or excessive nitrogen and manure applications.

Consider adding legumes, such as clovers, birdsfoot trefoil or alfalfa to help dilute fescue consumption.

Dividing the pasture into smaller areas and rotational grazing also will help.

Management of stands with 50 to 75 percent fescue should include clipping seed heads, minimizing N applications and incorporating legumes. Rotational grazing also would work

At this level of tall fescue composition, producers should consider sampling and testing fescue plants to determine the level of endophyte infection in the stand, which would enable them to make better short and long term fescue management plans.

At greater than 75 percent fescue population and/or where endophyte infection is known to exist and animal production is being affected, producers should begin to plan to kill the old stand and renovate the pasture.

Contact and ISU Extension livestock or crop production specialist when planning a fescue pasture renovation

*Taken from Iowa Farmer Today – June 16, 2001