Seed growers, researchers screen grass straw to protect livestock from fungus.
CORVALLIS, Ore. — On a typical summer day, Anita Holman, an Oregon State University faculty research assistant, will have around 1,000 tall fescue or perennial rye grass samples waiting in the laboratory for her and 11 student workers to test.
Their goal: to check if there is a toxic level of endophytes in the grass straw.
“After harvest starts, within two to three weeks, I’m a thousand deep in test requests,” Holman said.
Holman works at the OSU Endophyte Service Laboratory, one of the few labs in the world that test for the poisonous alkaloids in endophytes. An endophyte is a fungus that can live within a grass plant. It helps protect the plant from drought and pests. But the same bioactive compound that keeps pests away can also be harmful to animals that eat too much of it.
Past problems with overdoses of endophyte sickening livestock have sparked a heightened awareness among grass seed growers about the importance of testing the straw byproduct of their seed production before using it for livestock feed. The industry has now reached a balance by working together to protect animals and keep costumers happy, along with developing innovative new methods of controlling the toxin.
Three diseases are caused by endophyte alkaloids: ryegrass staggers, fescue toxicosis and ergot toxicosis. The ryegrass staggers cause muscle weakness, tremors and spasms in horses and livestock. Fescue toxicosis causes fescue foot — dry, dead tissue in the extremities; summer slump in which animals develop hyperthermia; reduced food intake; and reproductive and lactation difficulties.
Ergot toxicosis can cause diarrhea, high temperature, rapid breathing, poor appetite and weight loss.
David Bohnert, director of the Eastern Oregon Agricultural Research Center and a professor at OSU, has researched methods of alleviating toxicosis symptoms, such as giving animals seaweed extract or other compounds to help reduce the absorption of toxins.
Researchers, however, have found that while they alleviate some symptoms, they don’t eliminate all.
“There is no ‘silver bullet’ that will solve all the alkaloid problems seen with some varieties of tall fescue,” Bohnert said in an email. “Each product can be part of the overall tool box to help manage high-alkaloid forage; however, risk, cost and each ranch’s available infrastructure will determine what option, or combination of options, is best for that particular operation.”
In addition to impacting livestock, one of the three diseases, ergot, can decrease seed yield by as much as 10 percent, according to OSU researchers.
To combat ergot, they have been studying how weather conditions contribute to it by conducting spore trapping in perennial ryegrass seed production fields in the Columbia Basin. They found that the best time to apply fungicide is between May 15 and June 7 in a typical year.
Earlier this year, the program also received funding to investigate potential biocontrol options to manage ergot.
Burning to baling
Oregon farmers grew about 332,000 acres of grass seed worth $345 million in 2016, according to the USDA National Agricultural Statistics Service. Among the varieties of grass seed grown in the state are fescue, perennial ryegrass, annual ryegrass, bluegrass and bentgrass.
Before the 1990s, the straw residue left after grass seed harvest was typically burned to rid the fields of pests and diseases. However, after the phase-out of field burning in most of Oregon, straw is now baled and sold locally and overseas as livestock feed.
At first, some of the straw was exported to countries such as Japan, which reported the first cases of fescue toxicity. In 2000, 5,400 cases were reported in Japan, according to the OSU Endophyte Service Lab.
“The ships got stopped at the port because livestock was getting sick and it was traced back to Northwest feed,” Holman, the OSU faculty research assistant, said. “They wanted proof that the feed was safe.”
A solution was developed: Growers would test their grass seed straw before shipping it. Since 2009, the number of cases of livestock illness has dropped to zero, and has remained stable except for a few minor blips, according to Dr. A. Morrie Craig, a professor of toxicology at the OSU College of Veterinary Medicine. He also helped create the Endophyte Service Laboratory.
When Craig helped form the laboratory, he felt it would become a “world leader.”
From 2005 to 2013 the lab received an average of 3,497 test requests a year. Of the samples tested so far this year, only about 7 percent were positive for high toxin content.
The testing typically takes four days, and rush tests take two. However, the lab has been short one technician, which has slowed this season’s testing.
The test is a “19-step process to get accurate numbers, plus the lab has a second set of eyes to do the quality control,” Craig said.
Roger Beyer, executive director of the Oregon Seed Council, said it’s “essential” for grass seed growers to have a program to test the endophyte level, and that OSU is the laboratory of choice.
“Testing is crucial to the shipment of straw for feed,” he said. “There are other uses for straw, but not really for the amount we produce.”
Beyer said more than 600,000 tons of straw are exported each year from Oregon’s Willamette Valley.
“There’s a lot of unknowns in the world of endophytes,” he said. “Some people think we should establish different levels in varieties to eliminate testing, but every year environmental factors can change the levels of the endophyte.”
Because the level of endophyte isn’t solely based on grass varieties, Beyer said the industry has to test.
“We do our best to meet people’s needs,” Holman said. “It’s hard, it’s a lot of work, very detail-oriented, “but it feels good to know it makes a difference that you come to work every day; what we’re doing makes a difference on a daily basis.”
Benefits of toxins?
The same toxic endophytes that can make animals ill can also help prevent airline disasters. East Coast airports such as John F. Kennedy, Newark Liberty and LaGuardia have discovered that high-endophyte grasses have a natural insecticide that kills bugs. By planting the grasses around the airports, the insect population is reduced, attracting fewer birds. Birds are a hazard to airplanes, as they can be sucked into jet engines and damage them.
James Loudon, principal landscape architect in the Port Authority of New York and New Jersey Engineering Department, said in a blog created by the port authority that he and his team do “whatever we can to discourage birds, because birds cause the greatest threat to aircraft in flight during landings and takeoffs.”
“By limiting the edible delights of birds and the places they gather to feed and reproduce, we can discourage them from visiting the airports,” said Laura Francoeur, a wildlife biologist at the port authority. “Which goes a long way towards protecting the flying public from deadly bird strikes.”
Mountain View Seeds in Salem, Ore., is one of the few dealers that sell airports high-endophyte grasses, and has a system in place to verify the levels of endophyte before it is shipped.
“Endophytes are a living organism,” Aaron Kuenzi, executive vice president of Mountain View Seeds, said. “Over time it will just fade away.”
He cited an example of grass seed with a high level of endophyte sitting for five years in a warehouse. It could start at a level of 90 percent, but by the time it’s shipped the level could drop to 20 percent.
Mountain View maintains the correct level of endophyte by storing the seed in a cooler, and testing for endophyte presence before shipping it.
“We want to make sure that when we say it’s a high endophyte that … it actually is,” Kuenzi said.
While it is possible to develop fescue strains with little or no endophyte presence — typically referred to as “novel” — it is less attractive for grass seed producers because their primary product is the seed, not the straw. The endophytes help protect the grass plant from insects and dry weather.
Kuenzi said that it’s been great to have an alternative place for this seed production byproduct, but “ultimately, if we don’t satisfy the user or consumer of the seed, we won’t have production of the straw either.”
Mountain View Seeds has also developed non-endophyte varieties for its forage market with animal health in mind, but Kuenzi said less than 25 percent of its acreage is dedicated to it.
However, according to Bohnert, the OSU professor, that still represents progress.
“They have started moving away from more toxic endophytes and using the ones with lower (levels),” he said. “So, I think they are adjusting.”
Beyer, the seed council director, said that novel endophyte is the trend that the industry is working toward, especially for farmers who grow tall fescue as forage in their pastures.
“It’s an expensive conversion to get rid of endophyte grasses and put in novel (grasses),” he said. “But growing novel, we can grow it without testing it.”
He said that 17 to 20 percent of forage pasture and livestock regions have converted, and researchers say that acreage is increasing by 2 percent a year.
“We have a ways to go, but we’re working on it,” Beyer said.
Solution by dilution
Although researchers have yet to find a long-term management solution for endophytes, in the short term “solution by dilution” has been effective in keeping animals healthy.
“It is a good feed product if it’s used safely, but you have to know what you’re dealing with in the first place,” Holman said.
Bohnert suggests switching bales daily if endophyte is present, to give livestock a day off. He said it’s “the easiest (method) by far.”
Also, once farmers know the endophyte level of their hay, they can blend it with other types of hay that don’t have endophytes.
Controlling the endophyte is a delicate balance for farmers and ranchers, as well as for seed producers. Kuenzi has brothers who farm and understands the desire to grow only endophyte-free seeds, but he needs to think of his main customers first.
“It’s keeping in mind the ultimate product in this is the seed that goes to the marketplace, not necessarily the straw that’s harvested as a byproduct,” Kuenzi said. “For us, it’s finding that balance of satisfying the consumer and the farmer that’s growing (the seed).”
The one thing that everyone agrees on is testing for the endophyte toxin is crucial.
“A lot of people have become aware of the situation, the fescue problems are not like they were,” Bohnert said. Since 2002, “people have been very aware of potential problems. All you have to do is test, and if you’re feeding grass seed straw that has the potential of alkaloids, spend the money and have it tested so you can have peace of mind.”