Fescue is the Dr. Jeckyll and Mr. Hyde of Midwest forages. Its lush spring and fall growth provides a dependable forage source. But in summertime, fescue that is infected with toxic endophyte fungus takes a toll on livestock. Now a "friendly" endophyte may ditch Mr. Hyde once and for all. Except you can plan on increased management, too.

Fescue covers millions of acres in the Midwest and in its 60-some-year run as a utilitarian pasture forage, it has put millions of pounds of gain on the nation's beef herd. Then why is it that there is so much talk and print about "living" with fescue or trying to avoid it? Simple answer is that old stands of K31 fescue often host a fungus--Acremonium coenophialum--that produces compounds toxic to cattle. In common parlance, when a fescue plant contains this fungus, it is called endophyte or endophyte infected. "Endo" meaning "in" and "phyte" meaning "plant." The fungus lives between cells in the plant.

Midwest producers are familiar with the symptoms of endophyte-infected stands: When cattle graze severely infected fescue, the animals can experience increased body temperature, reduced conception rates and other problems. Increased body temperature is especially taxing on animals during summer months causing them to seek shade, stand in water and generally reduce grazing intake. Compounds from the fungus are also most concentrated at this time of the year, adding to the problem. The result is unaffectionately named "summer slump."

But for all the evil that the fungus releases on your cattle herd, it has also contributed to fescue's long-term success in so many pastures. The irony of Acremonium coenophialum is that it makes fescue hardier by providing insect, drought and disease resistance to the plant.

University of Missouri extension forage specialist, Rob Kallenbach, says that these beneficial aspects of the fungus are well documented through research. However, he allowed that some of fescue's persistence might be derived from the fact that when summer's heat slows down its growth and concentrates the fungus toxins, cattle don't eat as much of it. "It's hard to separate the effects of the plant's natural persistence versus grazing pressure," said Kallenbach.

Regardless of the exact source of its perennial toughness, the fact that fescue is so persistent has lent to its popularity. It seems built for abuse.

And abuse is what stands of endophyte-infected K31 fescue get. Producers are accustomed to being able to turn cattle into fescue pasture and have the grass withstand whatever pressure the herd gives it--and still be a viable stand the next year.

Before the endophyte fungus was understood, fescue surged onto Midwestern farms after its discovery in long-standing pasture in Kentucky. That discovery was back in 1931. After collecting and producing enough seed of the plant, a University of Kentucky scientist released a fescue cultivar in 1943, naming it K31 to represent its geographic origins and the year it was discovered. Soon K31 would be ubiquitous wherever the climate would permit. It represents much of our fescue pastures today.

Fescue's modern marvels
Endophyte-infected fescue has been around long enough for producers to figure ways to deal with summer slump. Diluting fescue pastures with legumes is a popular way to keep cattle grazing through hotter months. Medicated supplements like Fescue Equalizer can also stave off the effects of endophyte's toxins. But there has been a long quest to get to the root of the problem and avoid the fungus altogether.

One way is to store infected seed prior to sowing it. Research shows that the only way the fungus finds its way into new fescue plants is through the seed of the old, infected one. Because seed remains viable longer than the fungus, storing seed for a couple of seasons renders it endophyte free.

But K31 minus the presence of endophyte or cultivars that were selected especially to be free of the fungus haven't provided the cure producers hoped for. Without the benefits the fungus provides to the plant that aid in its persistence and with no toxins to discourage cattle from overgrazing, stands suffer and fall apart.

However, new cultivars are set to change perspective on fescue. Cultivars with the brand name MaxQ from Pennington Seed along with yet-to-be-released cultivar under development from the University of Arkansas in cooperation with the University of Missouri contain a "friendly" or "novel" endophyte.

The fungus provides its beneficial aspects to the fescue plant without creating toxins that affect cattle.

"Like people," said Kallenbach, "all fungi are individuals. Some that infect tall fescue are toxic. But there are naturally occurring ones that aren't."

To derive the new cultivars of non-toxic endophyte fescue, "someone isolated those fungi, then took endophyte-free plants and through tissue culture, put the endophyte in," Kallenbach said.

The switch
Friendly endophyte fescue is new, so producers are approaching with caution. One concern is how to kill old, infected stands. John Carpenter, a national sales manager for forage products at Pennington Seed, has one option.

"We recommend the same thing that has been proven for 15 years when you talk about eradicating

fescue," he said. Carpenter provided this recipe:

In spring,before the stand blooms or goes to seed, use a burndown that involves a systemic herbicide like Roundup. Then, plant a summer annual. Harvest the summer annual in the fall and apply another burndown to the stubble. After that, no-till the pasture with the new fescue. This regime is often called "spray-smother-spray."

Another concern is that friendly endophyte pastures will be invaded by endophyte-infected fescue.

According to Carpenter, there are two lines of defense on this front. First, it's critical to convert pasture that hasn't gone to seed in the prior year. Remember, the fungus lives in the seed and won't carry on if the seed stays dormant. Thus, seed that is in the soil for very long will emerge as endophyte-free plants.

Once established, fescue stands are tough competitors. Seed from fence rows and neighboring fields will have a tough time moving into established fescue stands.

Finally, cattle that have been grazing infected fescue that's gone to seed should be held off friendly endophyte pasture for three days. That gives time for them to pass any infected seed they've digested.

Carpenter admits that converting existing pasture with the spray-smother-spray method will be expensive--to the tune of $200 per acre including buying the fescue. But he said that grazing trials have shown the increased gain from non-infected pasture will offset costs quickly.

Cost is one thing David Carrier, a producer from Lockwood, Mo,. worries about. Carrier has 4 acres of Pennington's MaxQ fescue--a sort of test plot with seed supplied by Pennington. It was established in an old crop field, not in existing pasture and Carrier figures that's one way to avoid herbicide costs.

But after a good initial stand last fall, the pasture has blank spots this summer. Carrier sowed the fescue with an ATV, then made a pass with a cultimulcher, which probably left better seed-to-soil contact directly beneath its rollers. He fertilized the stand this spring but noted that so far, the new fescue hasn't responded as well as K31.

"We're learning about endophyte," he said. "Research will conquer that. We'll graze this stand and see what happens through another winter and spring. We'll probably hit it with 40 pounds of nitrogen in spring and give it a chance to produce. It has yet to prove itself, but after one year, I can't say, 'no, that's it.' Southwest Missouri has its effect."

Kallenbach reported that in University of Missouri plots at Columbia, MaxQ fescue is doing well this year. Plots in Knox County, Mo., however, suffered significant winterkill (but so did other cultivars at that site).

Great gains
Research from several universities (including MU's Southwest Center) has shown that cattle grazing friendly endophyte fescue can gain up to three times as much per day compared to infected stands. That's the return that folks like Pennington hope producers will figure into seed costs--set at about $80 per acre.

Kallenbach said that producers should take note of what increased gain means for the health of the pasture.

"One reason livestock gain more per day on novel endophyte fescue is that they eat more," he said. He added that producers need to understand that even though fescue contains friendly endophyte, they should be careful about over grazing.

"It will fit well into management-intensive grazing systems where grass is already being managed," he said.

From their different perspectives, Kallenbach, Carrier and Carpenter acknowledged that converting pasture to friendly endophyte fescue is a significant investment. As more acres are converted, it will become more obvious if that investment and the increased management it requires is paying off.