Research targets sheep industry’s biggest woe: pasture parasites


MORGANTOWN, W.Va. — While lamb and wool prices are at an all-time high, the sheep industry is facing a devastating threat in the form of destructive parasites.

“Parasites are becoming resistant to every drug we have on the market,” said Scott Bowdridge, an assistant professor of food animal production at West Virginia University. “It’s a huge, huge problem.”

Bowdridge, with the help of a $150,000 grant from the U.S. Department of Agriculture National Institute of Food and Agriculture, is working on a solution.


The answers may be found in the St. Croix hair sheep. As its name suggests, it’s a tropical breed and, according to Bowdridge, the breed developed under constant exposure to parasites. That exposure resulted in a super-charged immune response to assault from parasitic invaders.

“Unfortunately, the St. Croix has little to no commercial value in the United States,” Bowdridge explained.

Breeds like Suffolk are much more prized by America’s meat and wool producers, but the Suffolk sheep are relatively helpless in the face of parasitic assault. This is especially true for sheep raised on grass.

As the demand for grass-fed and organically produced lambs and wool increases, producers are even more threatened by animals lost to parasitic infection. Bowdridge is following a few different paths in his research.


One is the possibility of cross-breeding the St. Croix with commercial sheep species to see if their strong immune system passes down to the offspring. More importantly, he’s trying to figure out what makes the St. Croix sheep’s immune systems so robust.

“The St. Croix sheep launch an immediate, very aggressive attack on any parasite that enters their system, and you don’t see that in commercial breeds,” Bowdridge said.


He’s in the second year of raising and studying St. Croix sheep on WVU’s Animal Science Farm in Morgantown. The sheep were provided by colleagues at Virginia Tech, and they’ve been raised and studied at WVU’s raised-floor sheep facility at the farm.

The raised floor allows Bowdridge, along with three graduate and four undergraduate students, to control parasite exposure in the sheep and better monitor the animals’ response. He’s also working with WVU’s Organic Research Project.

Once Bowdridge has determined the mechanics of the immune response in St. Croix sheep, he hopes to work with private industry to develop dietary supplements that will trigger a similar boost in commercial sheep.

He’s currently in discussions with sheep industry leaders to secure private support for ongoing research and product development to supplement the seed funding from the National Institute of Food and Agriculture.

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