A mixture of fescue, Kentucky bluegrass, smooth bromegrass and perennial ryegrass will likely whet horses’ appetites and maintain productive pastures. That’s according to a first-year equine grazing grass preference and persistence trial conducted by University of Minnesota (U of M) forage and equine specialists.

The preferences of four horses taste-testing 12 cool-season grasses were recorded and analyzed by U of M equine specialist Krishona Martinson, forage agronomist Craig Sheaffer and grad student Beth Allen last summer. They also examined productivity and persistence during horse grazing.

Bluegrass is needed because animals prefer it and it’s persistent, Martinson says. “The bluegrass isn’t as high-yielding compared to other grasses, but that’s okay. We want it to be that base, that sod-former that withstands grazing and keeps that dense ground cover.”

The endophyte-free fescue provides moderate yields and, as with bromegrass and ryegrass, is persistent and “moderately” preferred by horses.

“Orchardgrass has long been the favorite of horse owners, and it does make phenomenal hay in a mixed setting with alfalfa, especially. But they just were not eating it well compared to the other grasses in our grazing trial. Looking at the yield and persistence, one might also want to include some orchardgrass just for a little bit of a yield bump,” she suggests.

Horses liked timothy, Kentucky bluegrass and quackgrass the most. Smooth bromegrass, meadow and tall fescue, perennial ryegrass and reed canarygrass were moderately preferred. Besides orchardgrass, the horses didn’t like Garrison creeping foxtail and two varieties of meadow bromegrass.

“Meadow bromes are really popular in cattle grazing circles, but the horses would not eat them,” Martinson says.

She excluded timothy as a top grass choice despite the fact that horse owners and horses like it – and that it was the most preferred grass in the trial. “Timothy, for a long time, has been the standard grass for horses and I’ve never really understood that. Maybe because it’s easier to identify?”

But it isn’t a grass that grazes well, the equine specialist adds. If pasture is overgrazed or grazed intensely, horses will kill timothy, which usually works better in hayfields with managed cuttings. She observed that grazing had thinned timothy and creeping foxtail stands.

In the trial, quarter horses grazed cafeteria-style on grasses in the vegetative-to-boot stages of maturity after plots were assessed for percent ground cover. After each of six grazings, from May through October, plots were mowed and allowed to regrow for about three weeks.

By the end of the trial, the researchers determined that timothy, perennial ryegrass and the two fescues had some of the lowest levels of fiber and the highest carbohydrate levels, partially explaining why these grasses were preferred by the horses. Orchardgrass, fescues and meadow bromes were most productive with yields ranging around 5-6 tons/acre.

“But last year we had perfect conditions for growing cool-season grasses,” Martinson warns. “We had so much rain that we grassed for six straight months and never saw a summer slump. We saw a bump in yield in those normal slump months because of the wet weather.”

The trial is now in its second year and she’s seeing similar results. Seed companies have been asked to submit grass seed and support for future annual trials.