The Iowa Stater, Sept. 1997

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The Iowa Stater
Sept. 1997

Stephen Ford

Cows pining for pine

Hungry cows in the West often turn to Ponderosa pine trees for their next meal, and many pregnant cows that eat pine needles give birth prematurely and the calves die. For years, researchers have been trying to figure out why.

That's where ISU animal science professor Stephen Ford entered the picture, collaborating with ISU graduate student Lane Christenson; University of Iowa's John Rosazza, Donna Farley and Mohsen Al-Mahmoud; and Robert Short, at a U.S. Department of Agriculture cattle research center in Montana.

The UI researchers did chemical extractions on the Montana pine needles, isolating various compounds for testing, and Ford and Christenson analyzed the compounds. Once a compound that was a potential culprit was found, batches were fed to late-pregnant guinea pigs and Montana cattle.

This cooperative effort led to the discovery of a set of compounds that slows blood flow to the cow's uterus, and thus oxygen and nutrients to the calf, and results in births three to four weeks early.

Ford said both fresh and dry pine needles contain fatty compounds that cause arteries and blood vessels to constrict. The discovery of this unique class of fats earned a patent for the six researchers earlier this year. Now they're working to find an antidote or a way to help cows digest these compounds without problems.

"We hypothesize the Ponderosa pine has developed its own defense, trying to kill off cattle herds to keep from being killed," Ford joked.

Susan Anderson, Ag Information

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