Goat grazing helps control buckthorn growth

Goat grazing as a means for removing invasive species has become an increasingly popular practice among midwestern landowners. At the same time, there's concern the goats may be spreading the invasive species they're eating through their feces.

University of Minnesota researchers addressed these concerns by feeding goats buckthorn fruits and recording how many seeds passed through their digestive tracts intact and able to grow. Their findings were recently published in the Natural Areas Journal.

"The study was inspired by questions from local residents who had been carefully observing goat behavior during browsing projects in public St. Paul parks," said study lead Katherine Marchetto, a postdoctoral associate in the College of Veterinary Medicine (CVM).

The study found:

• 2% of buckthorn seeds passed through goat guts intact;
• of the seeds that appeared in the goats' feces, only 11% were still viable.

For comparison, 63% of seeds that had not been eaten by goats were capable of growth.

"Our results show the risk of goats spreading buckthorn seeds between grazing sites is low, and that feeding buckthorn fruits to goats is actually an effective way to destroy the seeds," said study co-lead Tiffany Wolf, an assistant professor in CVM.