Jim Gerrish recalls his first try at swath grazing. He was concerned about the quality of his alfalfa swaths left out on the field all winter. What he got was a pleasant surprise.

"You get clear out to January and pull the swath open, particularly if it's under snow, and the fact that the alfalfa leaves are still on the stems -- that's a pleasant surprise."

As owner of American GrazingLands Services LLC (americangrazinglands.com/AGLS/), the renowned grazing expert works to educate producers about the possibilities of extending the grazing season.

"You need to look at all your grazing resources," Gerrish explains. "Swaths are one that will maintain quality well, so you can save them for later in the winter if you have other standing forage to put the cows on at the front-part of winter."

Swath grazing consists of grazing cattle on forages cut and left lying in windrows in the field. Also referred to as windrow grazing, the feed is metered out by using electric fencing to optimize its use and minimize waste.

When Ryon Walker, University of Minnesota Extension beef specialist, learned the growing season in Minnesota was just 120 days, he speculated that windrow grazing might help trim total feeding days.

There are a multitude of factors to consider for swath grazing but topping the list is an understanding of local weather and climate, the type of cattle you want to graze, type of forage to windrow and managing the swath, he says.

First, evaluate your area's "normal" fall and winter precipitation. "When you have forages lying on the ground, moisture can leach (or deplete) water-soluble carbohydrates, lowering forage quality," Walker says. Humidity makes it more difficult to cure swaths.

Experts say the Dakotas, Nebraska, Kansas, Montana, Wyoming, Colorado, Idaho, eastern Oregon and Washington, on down through the semi-arid West to New Mexico and Arizona, and even Minnesota and parts of Iowa, can successfully utilize swath grazing.

Producers often question the amount of snow cover cattle can forage through. Canadian research demonstrates cattle can forage through 2 ft. of snow.

"Once they know where those windrows are, they easily get through snow to that hay," says Jerry Volesky, University of Nebraska Extension range and forage specialist in North Platte.

But snow cover followed by warm weather in an alternating freeze-thaw pattern can leave an icy crust atop the swaths, making it difficult for cattle to get to the hay. When ice is a problem, driving a tractor down the length of the swath will break the crust, providing cattle access to the forage, he says.

But snow cover also has its advantages. Last year, Gerrish had 4-8 in. of snow covering swaths. "That kind of snow-cover actually locks in the quality (of the forage) at the state it was when the snow fell on it."
Understanding cattle's nutritional needs is important when evaluating the feasibility of swath grazing. Dry, pregnant cows are usually good candidates.

"During the fall, you're feeding a pregnant dry cow at a stage when her nutrient requirements are the lowest to maintain her body function," Walker says. Given temperatures at 20° F or above, the cow only needs about 8% crude protein to maintain body function.

"The later you go into winter, the more she'll need from a nutrient standpoint," adds Greg Lardy, North Dakota State University Extension beef specialist.

Calving date is also important. Gerrish swath grazes cows until they're moved into a bale-feeding situation to prepare for calving. He says cows can calve on swathed forages, but the forage must be tested for the energy and protein levels required for lactation.

Swath grazing also can work well for weaned calves in a preconditioning or backgrounding situation. In work comparing calves on swaths compared to bale feeding, Volesky found similar weight gains (0.55 lbs./day) in one year of a study. In the second year of the study, windrow-grazed calves had better gains (1.17 lbs./day) compared to bale-fed calves (0.86 lbs./day). The difference was attributed to the presence of high quality regrowth that was available to windrow grazing calves in November and early December.

What's more, Nebraska work found bale feeding calves cost 30¢/head/day compared to 16¢/head/day for swath grazing. Plus, the cost of baling was 37% higher than windrow grazing.

Meanwhile, Minnesota research found swath grazing cost 35¢/head/day compared to $1.26/head/day for baleage feeding.

To run your own cost comparison, visit: www.agric.gov.ab.ca/app19/calc/swathgrazing/production_info.jsp.

Gerrish also recommends forage sampling if producers want to swath graze stockers and replacement heifers. Supplementation may be needed if such animals will be on swaths longer than 45 days.

Windrow grazing works best in an intensive rotational grazing system, Walker says, with temporary electric fence controlling how much forage is available for cattle at one time. "The faster cattle are moved through with a limited amount of forage, the less they'll waste," he says.

Walker says it may take a day or two for cattle to acclimate to swath grazing because they gravitate to green, leafy material first. He determines his stocking rate based upon cows receiving approximately 2% of their bodyweight in dry matter.

In areas of heavy snowfall, Gerrish recommends heavy dense windrows so cattle can find them easier. Typically, swaths should be no more than 3-ft. wide. The larger the windrow, the more cattle are inclined to use it as bedding, especially when the snow flies, he says.

By raking windrows together, manure distribution is more concentrated around the swath and less between swaths. Dragging pastures in the spring to break up manure concentrations and residue is recommended.

For more on swath grazing, check out these resources: