Utah Researcher Teaching Sheep to Self-Medicate

When Juan Villalba scoops up some alfalfa pellets, his sheep know food is coming and start bleating and prancing with excitement. While they don't look particularly remarkable, these sheep could end up helping solve a growing global crisis that is threatening livestock worldwide: drug-resistant parasites.

Recent scientific studies have shown the number of livestock parasites that have become resistant to pharmaceuticals has been steadily rising. Internal parasites have been attributed to weakening and even killing livestock animals, such as sheep, goats and cows. Such infestations can create negative impacts on economies and food availability, particularly with meat and dairy.

In one of the first studies of its kind, Villalba, an associate research professor who studies foraging behavior at Utah State University (USU), is experimenting with using pastures as a natural pharmacy, where farm animals treat their own illness by eating certain plants with medicinal compounds. Researchers at USU have identified several plants that contain tannins, saponins and other natural compounds that can kill internal parasites.

More than a dozen sheep are penned in a covered area that Villalba calls "the cafeteria." Villalba is training sick sheep to associate eating medicinal plants - which often taste bitter - with feeling better. When the animals are placed in a pasture that contains those plants, the sheep have been observed seeking out those plants when they don't feel well.

"By offering animals choices, we allow them to build their diet as a function of their own needs," he said. As the animals recover, they stop eating the medicinal plants.

Researchers see it as providing livestock with their own personal medicine cabinet. Villalba has about nine acres of test pasture where he grows a mix of medicinal plants and alfalfa. He is currently researching what combination of plants is best for sheep.

Reprinted in part from chrom.com