Is the pasture greener on the other side? A curious horse investigates. MSU photo by Erin Raley.

Montanans love horses so much that they sometimes buy more horses than their pasture can handle, according to Bok Sowell, associate professor of animal and range sciences at Montana State University.

He's seen parents buy a horse for one child, for example. Then they buy another horse for a second child. Before long, the family has five or six horses on a pasture that can only handle three.

The outcome isn't good for the horses or the vegetation, Sowell said. Overgrazing can lead to increased parasite loads and a pasture overcome by weeds. If horses start eating sandy soil, they may suffer impaction which can lead to colic. If the family runs out of pasture, they spend money on feed.

Placing too many horses on a pasture is common, agreed Jennifer Mohler who teaches a pasture management class for horse owners in Gallatin County. The course is sponsored by the Gallatin Conservation District. Another big problem is horse owners who don't let their grass grow. They keep horses on a pasture too long or return them to a pasture too early.

"People need to consider themselves grass farmers. This is the crop you are trying to grow," Mohler said. "If you focus on grass, how to grow and harvest it, you can have a sustainable pasture."

To prevent overgrazing and related problems, Sowell spoke at MSU's 2004 equine conference. Many of his suggestions for grazing small pastures came from "Living on the Land," a CD developed by Extension Service experts and others in eight western states. The portion to which Sowell referred was written by Wendy Williams of the Montana Natural Resources Conservation Service in Bozeman and Holly George with the Cooperative Extension Service at the University of California.

Sowell gave specific numbers and amounts in his talk, but said figures can vary with conditions and animals. These were some general guidelines, however, for grazing small pastures:

* Don't let horses have non-stop access to forage areas. Two or three hours per day is enough.

* Create more pastures by subdividing grazing areas. Separate the areas with permanent or temporary fences, then rotate the horses among pastures.

* Monitor grass height. Horses should be moved when crested wheatgrass or Kentucky bluegrass are down to about two inches. The minimum recommended height for orchard grass, brome grass or Timothy grass is about four inches.

* Figure out how many animals a pasture can accommodate without overgrazing. Know how much your animals eat. As a general rule, a 1,000-pound horse will eat about 25 pounds of hay and grain a day or five tons a year when no pasture is available.

* Know how much hay your land will produce. Irrigated land is more productive than non-irrigated. One acre of irrigated land might produce one ton of hay under poor conditions, two tons under fair conditions and three tons under good conditions. One acre of non-irrigated land might produce about half that. If a pasture produces 17.5 tons of hay and forage, it will support about three horses year-round.

* Improve waste management so waste doesn't destroy or damage grass. Cleaning up manure may increase the amount of available forage.

* When no pasture is available, keep horses in a dry lot and feed them there.

* Control weeds and undesirable plants in pastures and nearby areas to prevent horses from getting sick. Houndstongue, for example, may be toxic to horses. If you don't know your weeds, contact your local county Extension agent. Mowing will control excessive growth of grasses.

* Whenever possible, let horses be horses. That means they should have space to wander and graze.

"A lot of time when you put animals in a real small space and don't allow them to graze, they develop nervous habits," Sowell said.

Posted by Evelyn Boswell for 11/17/04