Zebras versus cattle: Not so black and white

Sep 22, 2011
Grazing by wild animals doesn't always harm, and may benefit, livestock like cattle. Credit: Rob Pringle

African ranchers often prefer to keep wild grazers like zebra off the grass that fattens their cattle. But a new study by UC Davis and Kenyan researchers shows that grazing by wild animals doesn't always harm -- and can sometimes benefit -- cattle. The results are published Sept. 23 in the journal Science.

"Although savanna rangelands worldwide are managed on the premise that and wildlife compete for food, there is little scientific information to support this assumption," said Wilfred Odadi, a researcher at the Mpala Research Centre in Kenya.

"Our findings provide further evidence that biodiversity conservation and economic development can be simultaneously achieved in human-occupied savanna ," he said.

Cattle and wild animals like zebra: not always mutually exclusive on African rangelands. Credit: Ryan Sensenig

Truman Young, a professor of at UC Davis and senior author of the study, said the interaction between cattle and wildlife is more complicated than has been appreciated.

"When we look at the effect of wildlife on cattle, we find that they sometimes do suppress weight gain by cattle, but also sometimes enhance it," Young said.

"Generally the decision has been to exclude wild animals, but we're saying that things are not that simple," he said.

The researchers enclosed 10-acre plots of savanna rangeland inside fences to exclude wild animals (principally zebra). Then they weighed the cattle grazing inside and outside the fences to measure how much weight they put on at different times of the year.

The research team found that during the dry season, cattle that grazed with had reduced – the bottom line for ranchers. But in the wet season, cattle actually put on more weight when they grazed alongside wildlife.

This is a map of the study site in Africa where the research on ungulates and cattle was conducted. Credit: Truman Young et al.

The explanation is that during the wet season, can grow long and become rank, inaccessible and poor in nutritional value.

"When the grass grows very fast and is at risk of becoming rank, having zebras is beneficial," Young said. "They are more than willing to knock back the rank grass."

That means higher-quality, fresher grass for the cattle.

It's not yet clear whether there is a net benefit over a whole year or series of years, Young said, because conditions can vary considerably from year to year. Ranchers are beginning to explore additional ways to control rank grass, such as controlled burns.

Explore further: Nestling birds struggle in noisy environments

Provided by University of California - Davis

5 /5 (1 vote)

Related Stories

ARS scientists study effects of grazing on grouse habitat

Apr 30, 2010

Agricultural Research Service (ARS) scientists at the Eastern Oregon Agricultural Research Center in Burns, Ore., are taking a careful look at how grazing cattle affect sage-grouse habitat on high desert rangelands.

Study shows consumers find grass-fed beef acceptable

Aug 04, 2008

High feed-grain prices and the growing interest in "natural" foods have spurred both consumers and farmers to consider grass-fed beef, and a recent study done by Penn State College of Agricultural Sciences researchers may ...

GPS study shows wolves more reliant on a cattle diet

Mar 28, 2011

Cattle ranchers in southwestern Alberta have suspected it for a long time and now, GPS tracking equipment confirms it: wolf packs in the area are making cow meat a substantial part of their diets.

Canadian border cattle problem explored

Feb 23, 2007

The problem with hundreds of cattle imported from Canada with incomplete documentation involves record-keeping issues, U.S. agriculture officials said.

Recommended for you

Nestling birds struggle in noisy environments

Oct 29, 2014

Unable to fly, nestling birds depend on their parents for both food and protection: vocal communication between parents and offspring helps young birds to determine when they should beg for food and when they should crouch ...

The secret life of the sea trout

Oct 29, 2014

Jan G. Davidsen and his graduate students are spies. They use listening stations and special tags they attach to their subjects to track their movements. They follow their subjects winter and summer, day ...

Giant tortoises gain a foothold on a Galapagos Island

Oct 28, 2014

A population of endangered giant tortoises, which once dwindled to just over a dozen, has recovered on the Galapagos island of EspaƱola, a finding described as "a true story of success and hope in conservation" ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.