Some years, Ron Tombaugh gets several calls from dairy producers looking for good-quality oat hay.

“The demand varies from year to year,” says Tombaugh, owner of Dart Hay Service, Streator, IL. “It depends on the recommendations that dairy nutritionists are making to their clients. But the larger dairies are always looking for feedstuffs that are lower in potassium for their dry and transition cows.”

To ensure that potassium levels remain low, Tombaugh, who uses oats as a cover crop for new alfalfa seedings, fertilizes sparingly. With a little bit of alfalfa mixed in, the oat hay runs about 13% protein, he says. He harvests about 200 tons/year and sells it for $70-80/ton.

“If oat hay gets put up right, it has good feed value,” he says.

Tombaugh's comments echo those of Mike Hutjens, University of Illinois extension dairy nutritionist.

“Good-quality oat hay makes excellent dry cow feed if the ration's short of fiber,” says Hutjens. “Five pounds of oat hay has more feed value than straw or cornstalks. It can also be used in small amounts in lactating rations if more fiber is needed.”

If the oat hay will be used as an alfalfa substitute, he says it should be harvested at boot stage.

“But here in Illinois and other parts of the Midwest, it's almost impossible to get oat hay dry enough if you cut it in the boot stage. Small grains harvested in the boot stage can rival alfalfa in terms of performance, but we would have to make it into oat silage in this part of the country because of the moisture content.”

Bob Hilger is well-versed in the challenges of making high-quality oat hay, but says it's worth the trouble.

“It can fetch almost as much as high-quality alfalfa,” says the David City, NE, grower who enjoys steady demand for the small-grain hay from long-time dairy customers. “It's tough to get dry, especially if we've had a lot of rain. It can get almost as tall as I am and makes monstrous windrows.”

It may take several days for the oats to get dry enough for packaging in 4 × 4 × 8' bales, says Hilger. To speed drying, he lays it in wide swaths and rakes it at least once.

The Nebraskan, who grows the oats as a rotation crop for his 600-plus acres of alfalfa, says his dairy customers always request test results for potassium.

“Elevated potassium levels can occur on fields where a lot of manure has been spread,” he says.

Steve Woodford, a dairy nutritionist with Nutrition Professionals, Inc., Sheboygan Falls, WI, advises his clients to have their oat hay tested for potassium, calcium and phosphorus.

“The mineral composition can vary greatly, so don't just use book values,” says Woodford. “With dry or pre-fresh cows, the lower the better.”

It's important to have the fiber and protein levels tested, too, he reminds.

While the lion's share of Woodford's clients feed wheat straw, oat hay's a viable option to replace that or average- to low-quality hay.

“Oat hay matches up well with corn silage,” says the nutritionist. “It's a high-fiber, low-energy feed that can offset high-energy corn silage, plus it may have a lower mineral content than alfalfa hay or haylage. I have some clients who make oat hay or baleage; we use it in dry cow and heifer rations and it works well. I've used it in lactating diets, too, but that's not as common.”

In addition to having the mineral content analyzed, he cautions producers to have it processed fine enough so cows don't sort it out of the TMR.

“It's generally a little more on the mature side, so it can be tough to break up. You need a mixer that will really process it or grind it up ahead of time.”

For dry or pre-fresh rations, he recommends feeding 5-8 lbs/cow/day on a dry matter basis. “For a lactating ration, I would pull it back to about 3-4 lbs/cow/day,” says Woodford.