Early lactation cows like tall or meadow fescue added as part of the silage portion of their diets.

Producers may, too. Milk yields were maintained and, in some cases, even increased by 3-4 lbs/day in University of Wisconsin trials, says Dan Undersander, Extension forage specialist.

The bump in milk production may in part be a result of cows feeling better, he says. As dairies incorporate higher levels of corn silage into rations, cows consume more non-fiber carbohydrates (NFC). Corn silage, at 35% NFC, is high in starches and sugars. Alfalfa silage, at 25% NFC, is only less of a problem. When starches and sugars convert to acids, cows can get rumen acidosis and may develop foot problems.

“It’s like us eating nothing but candy bars,” says Undersander.

The solution is to reduce the NFC levels in the silage. At 12-14% NFC, grasses can do the trick, he explains. But because grasses have more neutral detergent fiber (NDF), too much of this type of silage could limit feed intake and lower milk production.

Wisconsin researchers worked to strike a balance between what’s good for dairy cows and what’s profitable for producers. They replaced 7% each of corn silage and alfalfa silage with 14-15% of a high-quality silage made of either tall fescue or meadow fescue.

The result: rations with higher total fiber and a fast rate of digestion, says Undersander.

Matt Bjelland has seen improvements in dairy herd health since he started adding an alfalfa-tall fescue mix to rations at Brown Star Farm in Gillett, WI. “When we add the fescue, the fiber in the feed is more digestible. We get a relative feed value of 150 and relative forage quality of 200 or higher due to increased digestibility. We milk 325 cows and have had only one or two DAs in the past year.”

Bjelland feeds a forage ration made up of 60% corn silage and 40% alfalfa-tall fescue mix. “We feed a lot more energy than we would with straight alfalfa.” Alfalfa at 40% NDF may have 45-50% digestible fiber, while grass, with 50% NDF, is usually 60-70% digestible, he says.

Tall fescue was initially interseeded into existing alfalfa. This year Bjelland seeded the two crops together at a 10-lb fescue to 10- to 12-lb alfalfa seeding rate. The key is to pick a fescue that matures at the same time as alfalfa, he emphasizes.

Compared to straight alfalfa, he found that the fescue-alfalfa mix packed more easily and more tightly in his bunker. Bjelland plans to reseed the alfalfa-grass mix every three to four years to keep the grass from taking over.

To get the system started, he worked with Daniel Olson, product development specialist for Byron Seeds. Olson says other growers are interested in the concept.

“Adding a tall or meadow fescue to alfalfa works really well,” he says. “Growers have been able to increase their yields consistently. The grass fills in around the alfalfa and provides better ground cover, while the alfalfa fixes nitrogen and feeds the grass. With the right variety and management, we are consistently seeing 40% more milk per acre.”

The high-energy forage may also lower feed costs, suggests Larry Hawkins, also with Byron Seeds, because it could replace more expensive corn and/or corn silage requirements.

Fescue is also more winterhardy than alfalfa and less sensitive to wheel traffic than the legume or Undersander’s old favorite, orchardgrass. It yields better than orchardgrass, too, he says.

Choose a fescue carefully. Aim for a highly digestible variety that offers a continuous yield throughout the season. Rust resistance is important. And in more southern areas, growers will want tall fescues with novel endophytes.

Strive for a 30:50 fescue-alfalfa planting ratio, or about 6 lbs fescue to 10 lbs alfalfa seed.

Harvest at a 3/8-¾” chop length and use a bacterial inoculant.

“At cutting, a fescue-alfalfa mix will feel and look different than straight alfalfa.” It also dries faster, so to harvest at 60-65% moisture, you may need to get into the field earlier than you’re used to, the forage specialist adds.