O&E Magazine

Cattle grazing in stream

Using precise tracking technology, a five-year study by OSU Extension Service found that cattle spend less time in streams than most people think—the average is between 1 and 2.5 percent of their time on the range.

John Williams, an Extension rangeland expert based in Wallowa County, Ore., and his colleagues used affordable GPS collars on beef cows allowing the researchers to map their positions over the paths of rangeland streams across five spring-to-fall grazing seasons. They discovered that the cows went down to the water when they needed to drink or cross, but did not typically linger there. They spent most of their time grazing on higher ground or resting on dry areas away from the stream.

The collars recorded the cows’ locations about every five minutes, yielding more than 3.7 million data points over the five-year study. “With this GPS technology, we can get a body of data we can really analyze, and we can start answering controversial questions with confidence,” Williams said.

Cattle grazing, especially on public lands, has been controversial at least since the 1980s, when ecological studies started to document the environmental damage done to rangelands from a 150-year history of livestock grazing. These findings and public pressure led to the adoption of grazing management practices aimed at protecting streams while still allowing livestock use.

The cows only used about 10 to 25 percent of the stream area, avoiding steep and slippery banks and inaccessible areas. Williams noted that all the study areas also contain non-stream sources of water, such as developed springs and ponds. In some months, cattle drank exclusively from these man-made sources, suggesting that they are useful range management tools that encourage decreased use of streams and riparian areas.

*The research was supported by the U.S. Department of Agriculture’s National Institute of Food and Agriculture; Agricultural Research Service; the Oregon Beef Council; the Oregon Agricultural Experiment Station; the University of Idaho; and the International Center for Agricultural Research in the Dry Areas.