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