If leafy spurge were good for cattle and the environment at large, such a strong will to live could be lauded.
But leafy spurge (Euphorbia esula L.) is a non-native, noxious weed from Eurasia that invaded the United States almost 200 years ago. As of 1998, the weed had consumed 2.5 million acres in North America. Infestations in Montana, North Dakota, South Dakota and Wyoming are estimated to cost $144 million annually, directly and indirectly.
Left uncontrolled, infestations double in size every 10 years.
Sheep love the stuff--once they acquire a taste for it.
But cattle--and cattlemen--can't stand it. Leafy spurge is toxic to cattle, causing severe irritation of the mouth and digestive tract in cows. It can result in death. Furthermore, cattle avoid leafy spurge infestations like the plague--refusing to graze the good grass growing among the weed infestations.
Two North Dakota State University studies supported by the American Sheep Industry Association, show how it could be done--and done profitably.
The studies found that a group of cattlemen could band together and invest in the creation of a sheep cooperative. The cooperative, with a professional manager, would be responsible for all aspects of the 5,000-ewe sheep flock--lambing, grazing, marketing and managing--while the investors could reap double rewards.
The sheep would spend the summer grazing leafy spurge infestations on land owned by the cooperative's investors. Afterwards, not only could the sheep be sold for profit, they also would leave behind a smaller and weaker leafy spurge infestation--allowing cattle to return to the area, the studies said.
"What these studies suggest is an opportunity to use leafy spurge, rather than eradicate it," said Tim Faller, the lead researcher and director of NDSU's Hettinger Research Extension Center. "For years, we have futilely focused on killing leafy spurge and the problem has continued to grow. It is time to change the mindset that killing leafy spurge is the only solution to this ongoing problem."
The studies found that a spring lambing flock could generate the cooperative an estimated net return of $124,000--not counting the economic benefits of improving the land. Cooperative investors with 50% equity and at least 50 acres of leafy spurge in a 100-acre pasture with a new fence could see a return on investment of 16%, the studies said.
The economic benefits of controlling leafy spurge with sheep could boost income per acre by up to $262 over 10 years, depending on the productivity of the rangeland, the amount of the leafy spurge, the grazing system used and the amount of fencing required, according to the studies. That figure includes returns from a sheep enterprise.
NDSU agriculture economists Larry Leistritz, Dean Bangsund and Randy Sell and Dan Nudell, a research specialist at the Hettinger center, conducted the studies.
Sheep producers have known since the early 1930s that sheep could consume and control leafy spurge while cattle could not, Faller noted.
Dennis Dietz remembers when his family used to run sheep on their ranch, near Sentinel Butte, ND. But over time, the family operation, about 10 miles from the Montana border, dropped the sheep in favor of cattle.
"They are too labor intensive and you have to have different equipment," Dietz said. The family ranch now runs about 200 head of Angus cows.
That is a familiar refrain to Faller.
If it is not labor and equipment concerns, cattlemen recite a litany of worries about managing sheep, keeping predators at bay and making sure sheep don't damage pastures or eat grass intended for cattle. Then there is the question of what kind of sheep, exactly, would work best and whether or not any profit could be seen.
"Those are the concerns we continue to hear today. Most North Dakota ranchers consider themselves cattle producers and focus their energies on that enterprise," Faller said. "That mindset is difficult to change."
But as North Dakota producers dropped sheep from their operations over the years, the leafy spurge infestations grew.
In the 1930s, there were less than 100,000 acres of leafy spurge in North Dakota and more than 400,000 ewes. Today, more than 1 million acres of North Dakota land are infested with the weed--and there are about 100,000 ewes in the state.
In 1994, NDSU Agriculture Economist Larry Leistritz, who also was involved in the sheep cooperative studies, estimated North Dakota had lost 11% of the state's cattle carrying capacity--equal to almost 600,000 AUMs--to spurge.
"That is enough grazing to support about 77,000 cows," Leistritz said, at the time.