State Weed Web SitesTry these web sites for additional information on leafy spurge and noxious weed control in your state:
Montana Weed Control Association
North Dakota Weed Control Association
Wyoming Weed & Pest Council
Q Where can I find good quality sheep to graze leafy spurge?
A. There are a number of breeders and livestock auctions in the northern Great Plains that handle high quality animals. Ranchers interested in grazing sheep as a leafy spurge management tool will need to do some planning. Those interested in raising and breeding will need to select good quality females and rams. When purchasing sheep or goats, select the breed and/or sex that best fits your goals and objectives.
Itís also a good idea to contact your county Extension agent for recommendations and guidance when expanding into a new livestock enterprise. Local Extension agents can sometimes provide information on local sources of sheep, and may know of sheep that are already trained to graze leafy spurge. In addition, each state in the northern great Plains has an Extension sheep specialist who can provide advice and information.
Q Can mature sheep intended for the kill market be used?
A. Absolutely. Studies show that sheep gain a lot of weight during a season of grazing leafy spurge. In fact, leafy spurge is high in crude protein and easily digested, and provides especially good forage for lactating ewes and lambs.
Q Will grazing leafy spurge impact normal sheep functions such as growth, breeding, etc.?
A. No. In fact, sheep grazing leafy spurge will actually outperform sheep grazing native range. This is simply due to the high quality of forage that leafy spurge exhibits.
Q Do I have to completely re-fence my operation, and do I have to use woven wire?
A.Woven wire is not required, but does prove excellent fencing for containing sheep or goats.Woven wire is generally the most expensive option, however, and other alternatives may provide adequate fencing at a more reasonable cost. These options include adding one or two wires to existing 3- and 4-strand barbed wire fences, and using 4- to 5-strand electric fence. Keep in mind that five to six stands are generally recommended for keeping sheep enclosed. Itís also recommended that perimeter fences be more substantial than interior fences. See pages 12-14 for more details on fencing.
Q What stocking rate is recommended, and how much diet overlap between cattle and sheep can be expected?
A. An average of 1.5 to 2 sheep per acre of leafy spurge for a four-month grazing season is generally recommended for leafy spurge control. This number will vary depending on the situation; see the discussion on page 16 for more information.
Dietary overlap will also vary depending on a number of factors, including plant types and species, diversity, availability, environmental conditions and the management strategies being used. An overlap of 10-12 percent can be expected, and may range as high as 70 percent. It should be noted that overlap generally remains low until a significant reduction in leafy spurge occurs; once infestations have been reduced, ranchers/land managers should consider reducing the number of sheep (or the amount of time sheep are grazed) to reduce overlap and competition for forage.
IT CANNOT BE OVER-EMPHASIZED that proper stocking rates, and subsequent range monitoring, are essential for leafy spurge management and long-term goals of range improvement. More information on diet overlap and stocking rates can be found on pages 16 & 17.
Q Do sheep need to be trained to consume leafy spurge?
A. There is some debate on this subject, and no clear-cut right or wrong answer. Many people believe that sheep need to be trained to enhance grazing results during the first year. Research studies using both "naÔve" and experienced sheep concluded that results largely depend on the diversity of the plant community (and sometimes the breed of sheep). Sheep are generally slower to accept leafy spurge when grazing in plant communities with a good diversity of broadleaf plants; in these situations, sheep eventually acquire a taste for the weed and will begin seeking it out.
Q What can one expect to see in the control of leafy spurge using sheep?
A. Typically, and depending on the type of grazing treatment and stocking rate used, you may see an increase in leafy spurge densities after the first year of grazing. A reduction should be noticeable after the second or third year. Depending on the management and growing seasons, 75 to 90 percent reductions in stem densities and canopy cover can be expected by years five and six. A year-by-year outline of what can be expected can be found on pages 6 & 7.
Q When should I begin grazing sheep on leafy spurge?
A. Sheep should begin grazing leafy spurge as soon as it reaches 3 to 4 inches in height, typically in mid-May. Turning sheep or goats out to pasture when the plant is 3 to 4 inches tall allows the grazers to prevent a majority of the plants from flowering and producing seed, and from developing dense canopy covers that inhibit the growth of desirable species.
Q What do you use for predator control?
A. Many techniques are used to reduce predation. Most common is the use of guard animals like dogs, donkeys or llamas. Using mature animals can also reduce predation losses for example, grazing dry mature ewes with cow/calf pairs. Other options include the use of a herder, and the use of trappin g and/or utilizationof local USDA-Animal Damage & Control personnel. See pages 15 & 16 for more details on predator control.
Q When using a rotational grazing system, should sheep be run before cattle or with cattle?
A. Sheep can graze with cattle, but some precautions are necessary. Producers that offer supplemental feed to calves may want to run sheep ahead or behind cattle in the rotation to prevent the sheep from consuming the supplement. Also, sheep are sensitive to copper. This may cause a problem in areas were copper is deficient and producers are using a high copper mineral program for their cattle; in this case, running the cattle and sheep separately is recommended.
Q Will leafy spurge come back if sheep/goat grazing is stopped after three or four years?
A. Yes. Unless additional control measures are taken to replace the grazing, leafy spurge will return to its original densities. The use of sheep as a long-term management tool is essential. Although you might not see any leafy spurge after 10 years, you still have a viable seed bank and viable adventitious roots.
Q If I implement multi-species grazing on my leafy spurge infested rangeland, do I need to do any spraying?
A. Absolutely. In fact, research shows that combinations of grazing and herbicides provide excellent results. In one study, angora goats were grazed from mid-May to mid-August, then removed to allow some re-growth. A mixture of 2,4-D and Picloram at a rate of 1qt + 1pt rate was applied in mid-September. This treatment worked extremely well, and has since been replicated with both sheep and goats.
Summary Table of Contents TEAM Leafy Spurge