Elk Study May Help
Cattle
By Kathryn Barry
Stelljes
June 24, 1997 Elk have yielded a secret that could
help rangeland cattle bear healthy calves even if they eat Ponderosa pine
needles during their pregnancies.
Scientists with the Agricultural Research
Service in Montana are the first to discover that pregnant elk who eat the
needles show no reproductive problems or constriction in their blood vessels.
University of Iowa and
Iowa State University researchers
collaborated in the study.
Scientists as well as ranchers have long known that problems arise for
pregnant cattle that eat the needles in the last trimester. Blood flow to the
uterus decreases dramatically. The cow delivers early, and her calves often
die. But elk apparently can neutralize the natural toxins in the needles.
Ponderosa pines, common on Western grazing lands, cover 27 million acres in
the United States. In 1988, the last available estimate, so-called pine
needle abortions cost cattle ranchers more than $20 million annually.
At ARS Fort Keogh Livestock and
Range Research Laboratory, Miles City, Mont., scientists are testing
several ruminants--including bison, sheep, goats and other grazers--to find
ways to prevent abortions in cattle caused by pine needle poisoning. Ruminants
are mammals whose stomachs have four compartments, the first one being the
rumen.
The scientists believe natural microorganisms in the elk rumen render the
needles harmless. Researchers are working to determine the differences between
elk and cow rumen flora, with the goal of reducing or eliminating the toxic
effects of pine needles. They also are evaluating bighorn sheep and
white-tailed deer.
In related work, the university-ARS team unexpectedly discovered--and
patented--potentially useful chemicals called waxy lipids in the pine needles.
These lipids appear to have no effects on pregnant cattle other than
restricting uterine blood flow. That might make them beneficial for treating
postpartum hemorrhages and other human ailments.
Scientific contact: Robert Short, USDA-ARS
Fort Keogh Livestock and Range Research Laboratory, Miles City, Mont., phone
(406) 232-4970, fax 232-8209, bshort@larrl.ars.usda.gov.
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