By BECKY TALLEY
Sheep Industry News Associate Editor

(May 1, 2008)  Targeted grazing is quickly becoming a hot topic amongst livestock producers and land managers alike throughout the United States. As invasive, exotic weed species continue to gain a strangle hold on many important landscapes and ranges, the focus is turning to the best way to control the spread with the least impact to the environment.

And increasingly the focus is turning to the use of livestock grazing.

“We started looking at this issue, and we found what was common knowledge 100 years ago, that grazing is an answer,” said Tom McDonnell, moderator at the first-ever Targeted Grazing: Grazing With a Goal workshop held in March in Albuquerque, N.M.

The workshop brought grazing educators, livestock producers, federal and state land managers and contract grazers together for a two-day information session on targeted grazing.

According to speaker John Walker, Ph.D., Texas A&M University, invasive plant species are estimated to cost more than $20 billion annually in economic damage and affect millions of acres of private and public lands.

These invasive plants often gain control of a landscape because they out compete native plants since they are not palatable for both livestock and wildlife, and they can’t easily be controlled by conventional methods, such as herbicides.

“The tools that we have are too small to manage acres of that scope. If we are going to manage a landscape, we need to manage it on a landscape level, not just with a back pack sprayer,” says McDonnell.

Grazing is starting to gain popularity because of the perceived benefits it provides. It is seen as more environmentally friendly than using chemicals, can be highly effective when done well, weeds are converted into gain for animals and it is feasible in rough terrain.

“Grazing is a powerful tool, and we want to use it for ecological goals,” relates Walker.

Targeted Grazing for Producers
In Montana, leafy spurge control has been a big issue, says speaker Lisa Surber, Montata Sheep Institute (MSI). The invasive species choke out forbs that affect the big game species, but also affect songbirds in areas infested with greater than 60-percent leafy spurge.

Grazing is an effective tool in this situation and sheep have been used to control the leafy spurge. Research by MSI has shown that for every year of successive sheep grazing a 7-percent reduction in leafy spurge and 5-percent increase in grass has occurred.

Results like these are quite common, and more land managers are looking at enlisting livestock, either as a stand-alone practice or in combination with other bio-control tools, to control weeds or as part of a fire-management plan.

However, before producers of sheep and other livestock decide to take on work as targeted grazers, there are several aspects of grazing to examine.

“You’re there for a weed-management goal, not a sheep-production goal,” says Surber.

Andres Cibils from the University of New Mexico discussed the role of animal husbandry for targeted grazing.

It is not as simple as rounding up a flock of sheep and turning them out into weeds, there is a science behind the method.

The first issue is choosing the species for grazing projects.

“You want to pick species better suited both anatomically and physiologically to the kind of plant you want to manage,” Cibils says. “In general, you can’t make cows do what goats will.”

Goats will browse and will focus on shrubs, etc. Sheep are more forb eaters, but will consume plants such as leafy spurge readily, and cattle will eat mostly grass while grazing.

However, these differences also make the possibility of running two species together an option. For example, according to Cibils, in a study of sheep and goats running together on a juniper range, the goats were more likely to focus on eating the juniper saplings when sheep were present. Sheep also are beneficial grazers on cattle ranches with leafy spurge problems, as sheep graze the spurge, eliminate seed production and decreased spurge concentration, which in turn increased grass production for cattle.

In addition to species choice, different breeds of animals will react differently to grazing and environmental conditions. Some will graze further away from water than others, and certain breeds will eat more of an invasive weed than another breed will.
Add on top of that inherited traits and behavioral conditioning, age, body condition and preference, and it begins to become clear that the science behind grazing is complex.

But by selecting and breeding animals with predisposed tendencies toward targeted plants and offering them nutritional and pharmaceutical aid to help them digest the plants, you can go a long way to creating a successful grazing tool.

“We can do a number of things to tailor the animal we have to the type of landscape we have,” Cibils relates.

Another consideration with targeted grazing is the grazing season. While livestock grazing for production generally sees animals go to the range at a certain date in the year, grazing management is entirely dependent upon the plant that is being controlled. It has to be hit at the time that will suppress the plant, but not cause overgrazing of desirable species in the area.

Once the target plant has been grazed, the livestock must be moved off of that land, so producers need to have somewhere to keep them until the next job. In addition, depending on what plants animals are grazing, nutrition requirements are a consideration, and on some targeted grazing projects the goal of weight gain or use of pregnant and lactating animals may not be possible.

In fact, grazing contractor and workshop attendee, Jason Garn of Utah, uses dry nannies for many of his grazing jobs, to avoid issues with nutrition needs.

However, as many producers have all the necessary equipment, knowledge and personnel to properly take on targeted grazing projects, they are poised to make grazing a value-added venture, if done correctly.

“They are equipped to do this, but they just need education,” says Rochelle Oxarango, workshop facilitator.

According to Rick VanBebber of the U.S. Forest Service, he has worked with grazers who are either in the project for weed management, or are participating in projects for livestock production. Both can work, but the grazers and the contract provider have to be on the same page.

“Some see an opportunity to augment their operation with grazing. Sometimes that is okay and sometimes it is only about pure weed control. You need to be clear on that,” he says.

One thing all participants agreed on, is that grazers need to have a clear idea of what the management goal is and be able to closely manage their livestock. A good and knowledgeable herder is absolutely key to this.

“You have to have someone who knows what they are doing,” says Garn, adding that for his contracts, at times have requirements such as English speaking herders for safety issues.

In addition, workshop speakers encouraged all who are interested in grazing to become educated on the subject and learn as much as they can to ensure successful weed management, which will in turn, encourage more land managers to consider targeted grazing.
“We have a lot of knowledge and a lot of information to work with. We’ve got a really good start, and I think we are breaking down those barriers that exist,” says Walker.
This workshop was also held in mid-April in Boise, Idaho, and will be held in Pennsylvania this fall. More information about the Pennsylvania workshop will soon be available on www.sheepusa.org.