MEDIA CONTACT:
Bill Loftus, Ag Communications, 208-885-7694, [email protected]
STORY CONTACT:
Karen Launchbaugh, Rangeland Ecology and Management, 208-885-4394, [email protected]
While Idaho and other state and federal agencies launch aggressive programs to combat weeds, rangeland scientists suggest sheep and goats offer a kinder, gentler weapon to supplement herbicides and other control methods.
But first, said Bret E. Olson, a range scientist at Montana State University, many people will have to get over an instinctual dislike of sheep in particular.
Karen Launchbaugh, a University of Idaho rangeland ecology and management professor, suggested that the war on weeds may even stir the need for new breeds of sheep or goats. Modern scientific methods could help breed animals selected specifically for their taste for troublesome weeds.
The two spoke during a symposium, "Grazing Behavior of Livestock and Wildlife," sponsored by the UI and held on the Moscow campus.
Launchbaugh and Olson reported on separate research projects that studied why or how grazing animals selected plants to eat.
Launchbaugh looked at whether grazing animals are predisposed by genetics to eat certain plants or whether they learn what to eat.
The answer is both nature and nurture. Research shows goats have a genetic tendency to favor certain plants. But animals learn which plants are good to eat, too, by experience.
Probably the best hope for capitalizing on sheep or goats for weed control, Launchbaugh said, is through genetic selection, much as people have been breeding livestock for millennia to select for desired traits.
"The most difficult thing about selecting animals for diets is determining what's in their diets. That's the biggest problem on breeding for that characteristic," she said. New methods can help researchers determine how much of a weed an individual sheep or goat actually ate.
If someone were to begin large-scale tests on sheep flocks in weedy areas to find which individual animals ate the most weeds, selective breeding could begin in a matter of months.
Another question remains about how much animals might zero in on particular weeds. "Do you need a flock that controls leafy spurge, one that controls knapweed and one that controls yellow starthistle?" Launchbaugh said.
"But it definitely seems to work. There are not only differences between breeds of sheep and even flocks."
A lot of the evidence flocks can be used to target weeds is based on observations by sheep producers. "It's definitely being done on the farm," she said, instead of through scientific efforts to create woolly Weed Eaters.
"Not only could we train or breed sheep, we could also give them compounds to help them digest toxic compounds found in some weeds," Launchbaugh said. "We could really create animals that would eat a lot of weeds. I'm excited about it because it gives us another tool to use with insects or herbicides."
"This is not rocket science," Olson said. "Their natural predilection is to graze these plants."
And pressing livestock into service to protect the environment isn't exactly radical, either. Olson noted that in California, officials in some areas are already drafting goats to eat shrubs and plants to lessen fire danger by reducing the amount of fuel available.
Many of those concerned about the current explosion of noxious weeds on private and public lands fail to make a critical connection. Olson said that the dramatic increase of noxious weeds since 1950s can be linked with a dramatic decline in sheep numbers during the same time.
>From the late 1800s to the 1930s, most of the Northwest was grazed, overgrazed in many cases, by sheep and cattle, Olson said. That early history of overgrazing by sheep of mountain pastures led many to resist the idea that sheep or goats could benefit rangelands.
But with more careful management, by moving bands quickly over the landscape, the past problems of overgrazing can be avoided, Olson said. The benefit is that sheep in particular prefer to graze on leafy plants, a category which includes most weeds.
Another point of resistance is the rise of cattle ranching. Running bands of sheep in their early years allowed many producers to put together large ranches. Many producers later shifted to cattle, which they saw as a step up, Olson said. Now many cattle producers swear they'll never allow a sheep on their places.
It is an attitude Olson finds ironic because sheep can benefit rangelands for cattle by controlling weeds and encouraging more grass growth, the favorite forage for cattle.
Current market conditions are squeezing cattle producers' budgets, Olson said, so the tendency is to spend less on spraying herbicides for weed control. But more weeds mean less grass in pastures and so the pastures can support fewer cattle, he said, meaning fewer sales. He believes sheep or goats offer a way out of this vicious cycle.
"What we need to do is have more sheep and goats and expose them to the weeds," he said.
BL--3/25/99
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