cover page title: Multi-Species Brazing and Leafy Spurge Manual
A comprehensive, easy-to-read manual on using multi-species grazing as an effective leafy spurge management tool.

Table of Contents

Diet Selection

The Objective

The primary objective of multi-species grazing is to improve grazing efficiency, or the utilization of available range resources, while maintaining or improving animal production.

As stated earlier, multi-species grazing can provide economic and ecological advantages over single-species grazing due to differences in dietary preferences and foraging behavior of cattle, sheep and goats. In general, cattle prefer grasses, sheep prefer forbs and goats favor shrubs. Since most typical rangeland includes two, and often all three, classes of vegetation, multi-species grazing may be more productive than single-species grazing – forage avoided by one species, for example, can be converted into profit by adding a class of livestock that will utilize it.

This scenario is especially true when leafy spurge is part of the plant community. Sheep and goats graze leafy spurge, consuming 50-95 percent of the weed’s above-ground growth, allowing desirable grasses to re-establish and be productive for cattle grazing. Other potential benefits include reduced leafy spurge control costs, potential profits from sheep or goat grazing, etc.

What Others Say...

TEAM Leafy Spurge believes sheep and multi-species grazing can be an effective component of integrated leafy spurge management programs. Here’s another view, from the American Sheep Industry Association.

"Sheep are a natural, low-cost means of managing America’s federal, state and private lands, even as they produce other resources, such as wool, meat and lanolin. Proper grazing can benefit the environment, wildlife, the tax-paying public, and consumers.

Noxious weeds are a major threat to both public and agricultural lands, killing surrounding vegetation and triggering soil erosion. The weeds not only make the land unfit for agriculture and cattle, they threaten to drive out native plant species and destroy wildlife habitat. Sheep are unique in that they readily consume plants other animals avoid or find toxic. As a result, sheep are used extensively to control noxious plants.

Leafy spurge is an invasive, indestructible weed that infests an estimated 3 million acres of farm and public lands in 26 northern states. The problem is particularly severe in Montana, Wyoming, and the Dakotas. While leafy spurge is toxic to most animals, sheep thrive on the weed. In Montana, the Bureau of Land Management (BLM) found that proper sheep grazing resulted in up to 90% control of leafy spurge, greatly reducing the need for costly herbicides.

Montana State University researchers report that sheep will also graze a variety of other noxious weeds. In the West, sheep can provide 85% control of spotted knapweed, another invasive and poisonous plant species."

Printed with permission of the American Sheep Industry Association, Inc. (6911 S.Yosemite St., Suite 200 Englewood, CO 80112-1414; 303/771-3500).
The ASI web site can be found at
To see this excerpt, go to the home page, click on “Fast Facts,” then click on “Facts About Sheep Ecology.”

In General

Numerous studies show that grazing cattle and sheep are complementary in intensive, rotational grazing of mixedgrass prairie. Most studies show that, when properly managed and monitored, multi-species grazing can result in stocking rate increases of 10-15 percent (either cattle, sheep or a combination of both). If leafy spurge is present, the increase is even more prominent – if spurge comprises 30 percent or more of the land resource, increased stocking rates (AUMs) of 30-40 percent for sheep may be achieved.

The key to effectively usi ng multispecies grazing is understanding the dietary and behavioral differences between cattle and sheep, recognizing seasonal variations, and properly monitoring and managing the range to balance grazing pressure and prevent potential problems like carrying capacity deficiencies and inefficient stocking rates.

Following are brief descriptions of dietary preferences for cattle and sheep:

• Cattle prefer grasses in all seasons regardless of availability. Based on research conducted on a variety of range types by researchers at North Dakota State University, season-long cattle diets average about 75 percent grass, 15 percent forbs and 10 percent shrubs or browse. Cattle will consume some forbs early in the season, but generally avoid most shrubs regardless of the season.

• Sheep are more opportunistic, and will graze a greater variety of plants in all seasons. Most studies show a preference for forbs early in the season and shrubs late in the season, while grass consumption can vary significantly depending on the availability of other preferred species.

Dietary Overlap

A key concern expressed by cattle producers when discussing multi-species grazing centers on dietary overlap. While this is a legitimate concern, especially forranchers who want to "save" grasses for cattle, research shows that dietary overlap can be managed and minimized.

Most studies show that, when properly monitored and managed, dietary overlapbetween cattle and sheep averages about 10-12 percent. This number, however, can be much higher depending on forage species availability and numerous environmental factors, again stressing the need for proper monitoring and management.

The degree of dietary overlap between cattle and sheep varies by season – it’s generally lower in the spring and early summer when more browse is available, and higher in the late summer and fall when considerable amounts of grass have been consumed.

In studies relevant to the northern Great Plains, most dietary overlap between cattle and sheep generally occurs in the fall or late fall for blue gramma, a common grass that it quite resistant to grazing. Cattle tend to prefer western wheatgrass and Junegrass early in the season, and western wheatgrass, blue gramma and Junegrass later in the season. The overlap generally occurs late in the season as sheep begin reducing their intake of forbs and increasing their intake of grasses. A common strategy to minimize this overlap, or competition, is to remove sheep from the grazing allotment before they begin increasing their intake of grasses.

In General........

Keep in mind that these are only general guidelines and that forage selection and grazing pressure can vary significantly depending on species availability, environmental conditions and other factors. Also, there are exceptions to every rule. Again, vigilant monitoring and proper management will help prevent potential problems.

EconomicsTable of ContentsStocking Rates

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