By Becky Kington, Montana Weed Control Association Executive Director and Dr. Lisa Surber, Research Scientist, Montana Sheep Institute.
The following is an interview that was conducted on October 23, 2009, between Becky and Lisa regarding targeted grazing.
Sheep grazing dalmatian toadflax, photo credit: L. Surber
Lisa, the MSU Sheep Institute has been involved in numerous targeted grazing projects in Montana over the past few years, and I have to credit MSI with elevating targeted grazing as an integrated control method for noxious weeds. How many targeted grazing projects have you [MSI] been involved with over the years and what specific weeds have been chosen to experiment with?
The Montana Sheep Institute (MSI) oversees approximately 15 targeted grazing projects with monitoring sites utilizing sheep and goats from multiple sheep producers. Montana Sheep Institute weed projects directly involved over 50,000 acres of weed-infested Montana rangeland and about 500 landowners. Currently major weed projects are targeted at leafy spurge, spotted knapweed and Dalmatian toadflax.
What have been some of the more notable projects?
Key project areas include 155 km of the Powder River, 40 km of the Yellowstone River, 13 km of the Madison River, the Deer Lodge valley area, and key support of the management program for the “Bucksnort” After-Fire project.
I was involved with the BLM Madison sheep project in its conception and while it is still ongoing today, I have to say that I’m not sure the sheep are as effective with knapweed as they are with other species, such as leafy spurge. Do the sheep seem to be more effective with certain noxious weeds?
Yes, there is a difference in the effectiveness of targeted grazing of different weed species. Most of these differences are driven by palatability compared to the native species we want to reestablish. A lot of people involved in weed control are associated with chemical control and that philosophy is to find a chemical to kill the plant and that plant will be gone for a length of time. Targeted grazing is a more subtle or refined movement away from that target plant. The strategy is a gradual shift in the landscape to the more desirable species. The goal is to graze the targeted species is such a way as to the target plant at a disadvantage to the desired species. So the palatability of the targeted plant to the sheep/goat plays a big role. When sheep grazing Leafy spurge they almost develop an addiction to it and grazing strategies are almost easy to develop whereas spotted knapweed is much more difficult. Sheep readily consume spotted knapweed but not at a much higher preference than the native grass and forb species.
There are other weeds showing great promise to be controlled very effectively using targeted grazing – Dalmatian toadflax and Sulfur cinquefoil. The MSI has 5 monitoring sites on Dalmatian toadflax infested areas being grazing by sheep and goats. We have see drastic reductions in Dalmatian toadflax on these sites. Dr. Rachel Frost and Dr. Jeff Mosley have a targeted grazing project with Sulfur cinquefoil and they are very encouraged with data from the first year of the project.
Sheep and goats tend to be fairly high maintenance, I mean it isn’t like you can just go grab a few lambs and stick them in your pastures. What is the average cost per acre with targeted grazing?
Commonly, in Montana it is suggested that the cost of targeted grazing is $4 – 8 per acre. However, typically these costs are not the same as “contract grazing”. In other parts of the country, Idaho for example, contract grazing for weed control can be higher in cost because the services will include all costs involved plus a grazing fee (i.e. trucking, herders, death loss, extra management costs). Contract grazers can be thought of just like contract spray crews. Most targeted grazing projects in Montana are a cost shared agreement between the landowner and the sheep producer. The landowner might pay for one-way of trucking or help with costs associated with camp tending.
If you wish to try using targeting grazing as a control method, what are the basic criteria to implement a program? (i.e. fencing, herder, necessary acres, predator management, etc.)
This is a difficult question to answer because it is different with every project. Under ideal circumstances, the sheep producer needs to be able to bring 800 head (a band) for 3-4 months for it to work economically for him; that would cover about 1 acre of infested area per sheep per month. The sheep producer will have a herder under employment already and will not need to hire additional herders. Additionally, in a new project area it is useful to be in close contact with Wildlife Services in case there are coyote problems. Sheep do water differently than cattle therefore there must be watering facilities suitable to handle the band of sheep all at one time.
The success/failure of a project is a direct result of all parties taking shared ownership. Each MSI project typically involves a group of private (Montana sheep producers, land owners, local organizations) and public (BLM, Fish and Game, Weed Boards) cooperators. Each year the monitoring data is shared with the parties involved and grazing plans are adjusted accordingly to improve the success of the project.
As with all methods of control for noxious weeds, there is no one silver bullet. What do you see as the benefits and drawbacks to targeted grazing and do you endorse integrated methods in conjunction with grazing?
There are many benefits of targeted grazing. Primarily, it is scientifically proven that targeted grazing is effective. Secondly, there is no chemical residues therefore it is a “greener” or more environmentally friendly approach to weed control. Targeted grazing converts weeds into a saleable product (i.e. meat). It has been suggested that given the current climate and societies view of herbicides that targeted grazing may be more sustainable in the long term. Targeted grazing may be the most economical method of weed control for large landscape scale infestations.
Targeted grazing does have some short comings. It does not work well in areas that have large predators like bears and wolves. As I mentioned previously, there are situations when the desired grass species are more palatable than the target weed. You can’t force the animal to eat the weed. Alfalfa, Smooth Brome, Kentucky Bluegrass, and lush re-growth will always be more palatable than the target weed. No matter what type of control or management tool employed to control invasive weeds there is always a potential for some non-intended risks.
The MSI always encourages the use of integrated method of weed control. Weed control works best when multiple measures are employed.
Recently, FWP issued a management plan for Big Horn Sheep that included a section on noxious weed control and targeted grazing. I know that the big horn issue prevented sheep grazing in the upper Madison early on; can you comment on what the Sheep Institute’s and Wool Growers stance is on this management plan?
The MSI’s stance is that the Big Horn sheep issue is a very complicated issue. Research is certainly not conclusive on either side. That being said we have always been sensitive to domestic and big horn sheep issues and have felt fairly confident that the risk of co-mingling could be managed. In several cases, in project development it was felt the risk of comingling could not be managed and those projects were not initiated. Unfortunately, in each of those cases the target weed is not being effectively managed currently.
There has been a very successful invasive weed project in the Deer Lodge area for years with no dire consequences to the stability of the resident Bighorn sheep population. In many cases where targeted grazing could be used the risk of domestic and Bighorn sheep interactions could be managed. In some of these areas the possible interaction with Bighorn and domestic sheep can be managed to the extent that the potential benefits to the landscape are much greater than the potential risks to Bighorn sheep. The FWP plan fails to recognize that this possibility exists.
We have had no documented cases where Big Horn sheep and domestics sheep intermingled on any of the grazing projects the MSI has been directly involved with.
In light of the economic, predator, and environmental plights facing producers today, how many producers are out there and available to offer targeting grazing options? Who are some of the bigger outfits?
There are numerous large sheep producers that are been used in targeted grazing project.
- John and Eric Lehfeldt
- Bob and Ben Lehfeldt
- Sven Svensson
- John and Nina Baucus
- John and Jerry Paugh
There are 32 state-listed noxious weeds, with more coming down the pike. Does MSI have any research projects in the works to experiment with some of the other state-listed weeds and targeted grazing?
Spotted knapweed, leafy spurge are the big ones. Exciting and promising data is being gathered on Dalmatian toadflax, Sulfur cinquefoil and common tansy.
Finally, a year or two ago, the Sheep Institute appeared to be on the Congressional list for chopping. What is the status of MSI and how stable is this program?
We have a lot of support from within Montana. All of our congressional delegation is extremely supportive. We received partial funding in FY08 and FY09 and currently funding for FY10 has come out of committee and is set to be approved. The reality is that the federal government is tightening these type of expenditures and the MSI is not a mandated program.
Tags: Grazing, sheep, targeted grazing