A Toolbox of Innovations to Control Small Ruminant Parasites

The growing ranks of ethnic groups across the South have spurred a sudden demand for specialty meats, particularly goat and sheep. Sales have been brisk. A wrench in the works, however, threatens the new businesses: widespread invasion of Haemonchus contortus, or barber pole worm.

The blood sucking parasite lodges in the animals' intestines, causing anemia, bottle jaw and eventually death if left untreated. Overuse of chemical dewormers has greatly increased the worms' resistance, making them almost impossible to control. One female can lay more than 5,000 eggs per day.

Thanks to funding from SARE, the Southern Consortium for Small Ruminant Parasite Control (SCSRPC) was formed to research and educate farmers on alternative parasite control.

The consortium's scientist, veterinarian and extension members developed a toolbox of affordable techniques that dramatically reduced the need for costly and increasingly ineffective chemical deworming agents.

A diagnostic tool called famacha is one of the consortium's important findings. The tool is a chart that matches eyelid color to anemia levels, an indicator of parasite infection. This allows farmers to target treatment only to infected animals, which in some systems has reduced use of deworming agents by 90 percent.

FAMACHA has become the standard in detection and costs only $10 for a card printed with the chart. According to Thomas H. Terrill of Fort Valley State University, one of the founders and current coordinator of the consortium, more than half of the charts - about 11,000 - have been sold in the United States. "It's an indication of how big a problem it is in the U.S.," says Terrill. "The farmers were desperate and it's a cheap, simple tool."

Linda Coffey, a goat farmer and specialist, says FAMACHA has had a great impact. "It reduces dewormer use, thus saving money, and it slows down resistance problems. Just as important, it allows the farmer to select breeding stock that is not anemic. That strengthens the flock over time."

Feeding copper oxide wire particles to parasitized animals is another promising method. Although reasons are unclear, this reduces infection rates in lambs and kids up to 90 percent.

Terrill is focusing on sericea lespedeza, a forage containing high amounts of tannins, which dramatically reduce parasites in many types of livestock. Terrill's project is one of a handful of SARE-funded research projects investigating the forage, including projects on an Ohio farm and at Louisiana State University. Another SARE project at the University of Maryland Eastern Shore is exploring high-tannin grain sorghum to control parasites.

Terrill says there is no silver bullet for parasite control. "It's a combination of tools. So we are moving into the next phase of trying to figure out the right anti-parasitic formula for each farm."

For more information, go to SARE's database of projects and search for LS02-143 (SCSRPS), LNE05-232 (UMES), GS07-059 and GS05-047 (LSU), and FNC05-564 (Ohio).

Want more information? See the related SARE grant(s) LS02-143, Novel Methods for Sustainable Control of Gastrointestional Nematodes in Small Ruminants, LNE05-232, High tannin grain sorghum as a possible natural anthelmintic for sheep and goats, GS05-047, Effect of a condensed tannin containing forage (sericea lespedeza), fed as pellets, on natural and experimental challenge nematode infection in lambs, FNC05-564, Grazing Forages High in Condensed Tannins and its Effect on Fecal Egg Counts in Meat Goats, and GS07-059, Effect of a grazing sericea lespedeza as a treatment padock for controlling natural nematode infection in lambs.