BURLINGTON (AP) - Rancher Dave Herzig has been experimenting with livestock feed, and he thinks turnips may be the answer.

"Turnips have 25 percent protein while grass is about 8 to 10 percent," Herzig said.

Herzig's family runs the Dakota Land and Cattle Co., along the Des Lacs River west of Burlington.

"In 2002, I began looking for a feed to increase grazing capacity," he said. "I read about experiments in Nebraska, including this mixture of oats, turnips and an annual grass called Italian rye grass."

The oats is seeded as early as possible, about May 5 to May 15, with a conventional drill. Then the turnip and grass seed is added with a surface air seeder. Herzig said he has seed shipped in from the West Coast.

The field is ready to be grazed about a month after it is seeded, he said.

"The cows graze the oats, a cool-weather crop, early. I let them chew it down from 7 inches or 8 inches to about 3 inches before they move," Herzig said. "The turnips don't come up early, so they eat the tops of them the second time through that pasture."

The herd of Hereford-Red Angus crossbred cattle moves through the irrigated fields, about 20 acres in each cell, in a 10- to 14-day rotation.

Herzig said the cows don't mind sharing space with the irrigation sprinklers, and they move to stand in the spray on hot days.

The Italian grass is a warm-weather plant, peaking in July and August, that replaces oats in the feeding rotation. It is cold-tolerant, however, so the grass can be grazed into November. It will sometimes turn green again after a light fall freeze.

"The cattle eat the turnips like candy," Herzig said. "They graze on the tops, but they will pull the whole plant and eat root and all."

Because tops are grazed off, roots often do not develop to the size one would expect in a garden.

Herzig said the system adds manure to the soil as well.

Calves are born in May. Dakota Land and Cattle Co. also has a feedlot, feeding its calves so he keeps close records on weight gain.

Herzig said animals on the turnip pasture weighed 35 pounds more in the fall than those on his other pastures, and he said conception rates were higher on those on the new pasture as well.

The cost of planting is about $30 an acre for seed and fertilizer, he said.

Herzig said experiment stations in Bismarck and Minot also are trying turnips as cattle feed.

The rancher continues to study ways to stretch feed capacity without buying more land, including a Canadian attempt in which ranchers swath hay and leave it in windrows in the field for the cattle to graze through the winter.

"I haven't tried it yet," he said, "but it's an interesting idea."