September 26, 2021

Game-changer: Novel endophyte fescue reduces herd health problems

MT. VERNON, Ill. — Livestock producers should choose forages based on their persistence when building a grazing system.

“We need forages that will persist in our environment, persist in the way we manage them and we need yield because we don’t want to be feeding purchased feeds,” said Craig Roberts, University of Missouri professor, plant sciences.

“The reason we have so much tall fescue is because it’s persistent,” Roberts said during a presentation at the Heart of America Grazing Conference. “Tall fescue is sort of water proofed because it has a waxy leaf so even after frost in October it stands up to everything but ice so we can extend the grazing season.”

Nobody in Missouri recommends a monoculture for pastures, said the state forage specialist. “People are using mixtures but we need a grass base and we need something that’s not toxic,” he added. “That’s why we’re so high on novel endophyte fescue.

“There have been very few real innovations in forages,” Roberts said. “In the ‘60s, it was Bermuda grass and grazing-type alfalfa, but novel endophyte fescue is something that completely changes animal performance.”

The toxins are always present in Kentucky 31 tall fescue. “The toxins are produced at high levels in the spring and fall,” Roberts noted. “In our state when calf prices are low, toxicosis costs $160 million every year and when calf prices are high it’s $200 to $220 million per year.”

Before converting pastures to novel endophyte fescue, Roberts said, the first step is to test for the endophyte in the existing plants. “That tells us how much of the farm we need to convert,” he noted.

“We have farms in our state that planted grass in the ‘60s and the endophyte was dead so we occasionally have a field that’s 15 to 16% endophyte,” he said. “Those are practically non-toxic so we don’t worry about them.”

Roberts recommends a chemical test from Agrinostics to determine the level on endophyte in a fescue pasture. “Make sure the technician knows what he is doing because a lot of things under the microscope look like endophyte but are not,” he stressed. “We don’t want to spend money renovating a field that is not very toxic so we need to know field by field.”

To renovate a pasture, producers need to do more than just spray to kill the forage because there are escape tillers.

For the conversion process, Roberts recommends spraying a field with glyphosate at the end of the spring. “Plant a smother crop such as pearl millet or sorghum-sudan and spray again in late August,” he added. “Then no-till a novel endophyte.”

It is important to plant a summer annual and not any type of forage that forms a carpet, Roberts explained. “We need the wide rows of crops with grains because in between the rows you’ll see escape tillers from volunteer seed coming up and those must be hit with the second spray,” he added.

Plus, the summer annual provides a source of high quality feed. “There is no feed like an annual for fiber levels and digestibility. Annual grasses are incredible compared to perennials.”

Instead of converting all of the pastures to novel endophyte fescue, another idea is to convert 25% of them.

At the University of Arkansas, a study compared a system with 25% novel endophyte and 75% toxic to 100% toxic pastures and 100% novel pastures. The cattle were grazed in the novel endophyte pastures one month before breeding until the end of the breeding period.

“With the toxic fescue pastures the calving rate was 44% but they got 80% calving rate with just 25% novel fescue,” Roberts reported.

However, Roberts said, there are still problems with birth weight and weaning weight. “A study from Clemson showed birth rate can be as low as 30% less and weaning weights 56 to 110 pounds less for straight fescue,” he noted.

“If there are two systems — a toxic system and a non-toxic system — then a lot of management has to happen,” Roberts stated. “Don’t let animals graze mature toxic seed and then come back onto the novel because the cattle will plant it through their feces.”

The novel endophyte fescue can be phased into a grazing operation. “Some farmers are doing 10 to 15% of the farm each year and that will take about eight years to get the fields converted,” he said. “Novel endophyte fescue is a 100% cure for fescue toxicosis.”

Martha Blum

Martha Blum

Field Editor