The Endophyte Lab: 25 Years of Helping Grass Seed Growers Turn Challenges into Opportunities

Tall fescue harvest in Tangent, Oregon.

By Vince Patton


ew regulations often carry unintended consequences—and new opportunities.

When Oregon began to limit field burning in the Willamette Valley in the 1990s, grass seed growers needed a new way to get rid of the straw left in their fields. They quickly discovered a healthy export market in Japan, Korea, and Taiwan in need of hay bales for cattle feed. But with that new business prospect, a hidden threat was exposed. The endophyte, a small fungus endemic in grass seed, creates toxins that can harm livestock.

To better understand and manage endophytes and help industry safely provide hay bales to emerging Asian markets, Oregon State University’s College of Agricultural Sciences launched the Endophyte Service Lab.

“Out of necessity this industry was created,” says Matt Eide, General Manager of Quality Trading, which processes and exports forage for more than 30 Oregon farmers. But Eide says grass straw exports eventually hit a major snag. “When Japanese customers realized there was a problem with endophyte toxicosis, they demanded we prove our straw did not contain toxic levels of endophytes.”

“Endophyte” simply means “in” (endo) the “plant” (phyte), and it presents a classic paradox of nature. Endophytes create toxic compounds which help the fescue, but can harm animals that eat the grass.

Tall fescue, Oregon’s largest seed crop, often carries a minuscule fungus hiding deep between its cells. “Endophyte” simply means “in” (endo) the “plant” (phyte), and it presents a classic paradox of nature. Endophytes create toxic compounds which help the fescue, but can harm animals that eat the grass.

“It’s not a contaminant nor has it been intentionally put in the plant,” explained Jennifer Duringer, director of the Endophyte Lab. “Endophytes have been part of the grass seed industry for as long as we’ve been cultivating the crop.”


Grass seed harvest central Willamette Valley, Oregon.

When Benefits Cause Harm

Fescue and endophytes get along very well. The fescue spoon-feeds nutrients to the fungus. The fungus reciprocates by producing mycotoxins—chemical compounds that help the fescue stave off insects and survive drought and stress. It does better in drought by rolling its leaves, conserving water, and also shows better root growth. To handle pests, Duringer says the fescue “can’t get up and run away from herbivore predation,” so it has evolved to use the mycotoxins to fight off insects.

For fescue destined for turf in lawns, ball fields, and golf courses, the extra protection of endophyte fescue is highly beneficial. But not if the grass is destined to feed cattle.

Some of the bioactive compounds that endophytes produce—ergot alkaloids—are toxic to livestock that graze the grass or later eat the straw or seed pellets derived from fescue. Ergovaline is the best-known ergot alkaloid, and it has been directly linked to fescue toxicosis in cattle.

Researchers have called fescue toxicosis the number one large animal toxicity problem in the United States. Significant impacts from toxic fescue include:

  • Bovine Fat Necrosis: Masses of hard fat cause digestive and calving problems.
  • Fescue Toxicity: Constricted blood vessels that impair body temperature. In summer heat, cows pant, spend more time in shade or water and eat less rather than grazing.
  • Fescue Foot: Gangrenous conditions of body extremities.

And while less common, fescue toxicosis can prove fatal to cattle when toxicity levels are too high.

For ranchers, managing toxic fescue can dramatically drop productivity. A cow that gains less weight than typical or fails to produce calves, costs money.

“If they’ve got a hundred animals,” says Duringer, “and maybe they only produce one or two less, that still impacts their bottom line.”

A number of studies have shown that cattle with fescue toxicity gain 50 to 59% less weight than cattle with non-toxic diets. The Oregon Tall Fescue Growers estimates fescue toxicity is so widespread that it costs the U.S. beef industry $1 billion dollars annually in reduced production.


The Economic Impact of Science

Given that Oregon is the nation’s top producer of fescue seed shipped all over the world, this dilemma has global implications. Across the U.S., more than 35 million acres are planted in tall fescue. Most have toxic endophyte-infected grass. But there is no way to tell by glancing at a field if it is infected with endophytes. Only laboratory analysis can detect it.

In the late 1990s when the Endophyte Service Lab was launched at Oregon State University it was one of the only labs where growers could get their grass tested for endophyte toxins throughout the year.

And it still is.

Eide at Quality Trading says the Endophyte Service Lab has become integral in making it possible for the Willamette Valley to export 700,000 tons of straw per year.

“The lab is a very important part of making sure we ship safe feed.”

Duringer’s lab runs an estimated 3,000 tests each year for grass-growing clients in Oregon, Washington, Canada, and even Europe. Many of the regular clients represent multiple farms, and co-ops are also turning to the lab more frequently. Other labs test for ergot alkaloids for the purpose of research but not directly for the grass industry.

“There’s just not many labs that do this assay in a service sense,” says Duringer.

Jennifer Duringer demonstrates some of the equipment
used to help the grass seed industry at the endophyte lab.

And no other labs can handle the volume that Oregon State does.

Because the purpose of this testing is in response to industry need, there is constant communication with growers to evolve the program. Most recently, for example, a survey in the Willamette Valley found endophyte compounds in pellets, so the lab is now also testing that feed material as well.

Testing for endophyte toxins starts at the farm where bales of hay are treated like a geology experiment. A core sample grabs hay from the surface and deep inside. The lab can also test feed pellets made from grass and seeds. The time-consuming testing first requires grinding up the grass or seed down to the consistency of flour. After freezing and storage, the samples are subjected to an organic solvent extraction to remove unrelated waxes, chlorophylls, and pigments. The samples then are spun, pulling off the solvents, leaving extracts captured in tiny test tubes barely more than one inch high. These vials get loaded into a machine that uses High Performance Liquid Chromatography (HPLC), a method so precise it can detect ergot alkaloids in the parts per billion. Quantities that small can still prove toxic to livestock.

In its early years, the Endophyte Service Lab tested about 40 samples per week. Now, according to Duringer, in the height of summer the lab will do 300.

Summer is such a high season for testing, Duringer adds staff which provides experiential learning opportunities in the lab for up to 10 undergraduate students every year. With five HPLC machines running simultaneously, they can turn around tests in less than two weeks. During slower parts of the year when staff is reduced, tests can take three to four weeks.

Grass seed producers who have endophyte-free fields don’t have to worry about an invasion from outside. Endophytes do not travel by air. Infected plants come from infected seeds, so it is important to know what they are planting. However, endophyte-infected fescue is heartier and can out-compete non-infected fescue, taking over a field.

As the lab continues its testing, most growers understand that if they land a high-endophyte toxin reading, they should not bail those fields for livestock.

As Duringer notes, “It’s better to just do the testing than get surprised.”


Real Solutions. Real Impact.

One of the most satisfying aspects of the work Duringer leads is the ability to see immediate impact and value with growers. They don’t need to wait 10 or 20 years to see the impact. They know that the lab tests they perform make a multi-million-dollar export industry possible.

This deeply connected relationship between the agricullture and natural resource community and scientists at the College of Agricultural Sciences reflect the continuing value of the University’s land-grand mission. The problems researchers aim to solve are not theoretical, they have real-world benefits for producers and the communities and families that rely upon them across Oregon and beyond.

A quarter of a century of testing has proven invaluable and created lasting relationships between the university and farmers. Eide added, “If it wasn’t for Oregon State and some dedicated members of industry there would have been a real, real problem.”

1 comment

  1. I have aPaenibacillus polymyx that is a nitrogen fixer that we are interested in applying to forage grasses. I would like to know if it produces an alkaloid which would be toxic to cattle. Could you test this for any toxic compounds? I would be interested in working with you to investigate endophytic microbes with beneficial properties that might have detrimental toxicities. Thank you so much, Mark Roberts

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