New fescues end toxin damage

For openers, Craig Roberts tells farmers that toxic endophyte in fescue costs the Missouri beef industry $160 million each year.

Now, the University of Missouri Extension forage specialist can add good news to his story. Several new fescue varieties without the toxin are coming on the market. That may help reduce the cost of replacing the toxic K-31 fescue that dominates Missouri pastures.

If beef-cow herds look nastier than they have in years, it is their way of saying “We have too much toxin in our bodies.” The combination of infected fescue and record-breaking heat this past summer hurt cow herds more than ever.

Key Points

New fescue varieties coming to market are offering relief from toxin stress.

Novel endophyte replaces toxic varieties, protecting plants and animals.

Watch for release of even more varieties and research results in the state.


A pregnancy check when it is cool enough to work cows may help cull those that lost pregnancies from heat stress. No need to feed an open cow this winter. After wallowing in mud, some cows this summer looked more like barnyard sows than grazing beef cows.

The toxin from infected fescue reduces the cow’s ability to cool off. Those that can, stand in ponds and streams to “chill out.” Those denied access to bodies of water create their own mud wallows. By sloshing water from tanks and adding their own urine, they create cooling mud.

Muddy cows and calves look ugly. A clean planting of the novel-endophyte fescue in pastures can beautify the herd.

An even better reason to change grass is to boost your calf gains, reduce embryonic death loss and boost milking ability of cows.

New fescue ‘beneficials’

Plant breeders have come a long way since George Garner, an MU ag chemist, identified ergovaline as the toxin in K-31 tall fescue back in the 1970s.

The endophyte fungus that grows between fescue plant cells makes the toxin that helps fescue survive. It repels diseases and insects. The toxin even slows cows from eating too much fescue. That’s why K-31 survives so well. Cows won’t grub it into the ground, if they have any grazing choices.

At first, plant breeders eliminated the endophyte. The excitement of that breakthrough was short-lived. Fescue without the toxin didn’t survive under casual grazing management. Cows grazed it to death.

Next came an endophyte that protected the plant, but didn’t produce toxins that harmed cattle growth, reproduction and milking ability.

New Zealanders discovered the MaxQ endophyte, a beneficial. It was bred into the Jesup variety that was endophyte-free. That became the standard. It became the variety recommended by MU forage specialists for use in Missouri.

It is a productive perennial cool-season variety — but a bit pricey. Producers have been slow to adopt it, not so much because of cost, but from not knowing what K-31 costs them every year.

New varieties arrive

Pennington Seed now has Texoma MaxQII. The cultivar came from Noble Foundation in Oklahoma and thrives in states south of Missouri. Research is being conducted to see if it will work here as well.

Barenbrug Seed of Oregon has released BarOptima Plus E34. Its plant breeders screened all varieties to find an endophyte low in toxin. The E34 was inserted into fescue with high digestibility and soft leaf traits. The breeders developed the endophyte and plants together.

“The breeders did not simply inoculate an established variety,” Roberts adds. In university trials, E34 has shown good results and persistence. “This is different,” Roberts notes. The E34 contains low levels of toxin, but not enough to hamper grazing performance.”

DLF International Seed, also from Oregon, will market DuraMax Armor. This development from Auburn University will be suited in the fescue transition zone, which includes Missouri.

“Look for this one as it arrives in Missouri this fall,” Roberts says.

The Armor endophyte was found in North Africa and is licensed by the University of Arkansas.

It does not contain an alkaloid that harms livestock, but it does have one that repels insects. It is still undergoing variety trials. A couple of other cultivars are in the pipeline from Kentucky.

“Watch the news,” Roberts says.

‘Spray, smother, spray’ is still effective

Replacing infected K-31 fescue with a new toxin-free variety takes planning and working ahead, warns Craig Roberts. In a talk at the 2011 University of Missouri Bradford Farm field day, the Extension forage specialist asked crop advisers to help spread that word.

The key words are “spray, smother, spray.” The technique has a long history of working. But, too many take short cuts. Researchers are working on shortened protocols; but for now the five-month course works. New six-week recipes fail in Missouri.

The spray-smother-spray plan can work in fall or spring seeding. Still, Roberts favors fall plantings. “Seed in the fall, or not at all,” he advises. Weed competition fades away in autumn, compared to spring. That can be a make-it or break-it decision.

He recommends spraying in May, after fescue has been harvested — grazed or hayed. Glyphosate works well in killing the K-31 fescue stand. Then, no-till in the “smother crop.” Tilling or plowing just brings up a fresh supply of dormant seed from the soil seed bank.

The smother crop can be millet, forage sorghum or a similar summer annual. Those supply forage to fill the summer grazing gap. Before seeding time in the fall, harvest the smother crop. Then apply the second application of glyphosate.

Wait awhile after harvesting, and hope for a rain to bring up another flush of fescue seedlings — the target of the second spraying. The fall spray also gets any escaped tillers missed in the spring.

The smother crop, and dry weather, take care of the seedlings that sprouted during the summer. The summer annuals shade out and take moisture away from the seedlings.

A reservoir of infected seeds and protected tillers are under cow pies. Over summer, those cow pies dissolve, exposing infected tillers to the second spray. Cow pies alone protect enough infected fescue to defeat a new seeding, Roberts says. That’s why replacement takes time.

All of the tips on correct seeding depth and timing for establishing a fall seeding must be followed. Consult a regional Extension agronomist for help. Also, ask about seeding rates. Seed companies will be suggesting generous seeding rates.

For now, be wary of shortcuts, Roberts says. The full spray-smother-spray does work. A six-week treatment works in New Zealand, which has a different growing season with a steady supply of moisture, which reliably brings up seedlings from the soil seed bank.

In Missouri, six weeks of summer can pass without enough rain. That won’t bring on the infected seedlings to be killed by the second spray. Fall rains do that in Missouri.

Roberts says some new tactics are being studied. Those include “mow, mow, spray, spray.” Stay tuned for results.

Grazing school gets you up to date

To learn the latest on grazing management, sign up for the state grazing school at Linneus. That’s the school where instructors for regional grazing schools catch up on the new twists in management-intensive grazing.

The school runs Oct 4-6 at the University of Missouri Forage Systems Research Center in north-central Missouri’s Linn County. Anyone can register to get the newest ideas from the researchers and master graziers. For more information, visit the website, aes.missouri.edu/fsrc, or call Joetta at the Missouri Forage and Grasslands Council office in Columbia at 573-499-0886.


This article published in the September, 2011 edition of MISSOURI RURALIST.

All rights reserved. Copyright Farm Progress Cos. 2011.