Small ruminants are managed very differently from their larger grazing livestock counterparts and come with some unique challenges. Sheep and goats need substantial fencing, protection from predators, and periodic hoof trimming, to name a few husbandry requirements. Still, the biggest challenge sheep and goat producers face is internal parasite management. The stomach worm, Haemonchus contortus (aka the Barberpole worm), is the #1 nemesis of southeastern small ruminant ranchers, causing decreased production and deaths across most herds. To be successful in raising sheep or goats, producers must familiarize themselves with current management techniques. Here are a few tips to help you win the battle against internal parasites on your farm.
- Maintain strict quarantine and sanitation practices. Separate new animals and treat for stomach worms as needed before introducing them to the rest of the flock. Some parasites, such as coccidia, are spread through animals eating from fecal contaminated feed troughs or water sources. Feed up off the ground, keep water fresh, and clean manure from feeding and bedding areas frequently.
- Select genetically resistant animals. Breeds such as Kiko goats and Katahdin sheep are known to be naturally parasite resistant. Some animals within each breed are more resistant than others. Selecting for these animals over time and buying males that have parasite resistance (have not had to be dewormed but have been exposed to worms) can go a long way towards genetic control.
- Rotate pastures and graze only grass above 4 inches high. Cultural controls are where farms can see the biggest impact in parasite suppression by reducing establishment, reproduction, distribution, and survival of parasites. Worm larvae migrate from animal feces up blades of grass where animals re-ingest the larvae. The rate at which they are ingested can be controlled by intensive pasture management, including using reasonable stocking rates. Rotating sheep and goats off a pasture when the grazing is still at least 4-6 inches high decreases larval ingestion.
- Use natural enemies to fight pests. Nematode-trapping fungus (Bioworma®) is a new tool recently available in the U.S. that interrupts the life cycle of parasites by trapping (and killing) larvae in the feces. Forages with high levels of condensed tannins, such as sericea lespedeza, also help lower infections.
- Do NOT deworm on a schedule. All living organisms adapt to their environments, leading to slow changes over time. Overuse and misuse of dewormers speed up changes, and resistance to deworming drugs is a widespread problem. Small ruminants will always carry some level of parasite burden. The goal should not be to create a parasite-free animal, but to prevent clinical signs and production losses in a herd/flock. Through the use of the Five Point Check © (which includes FAMACHA© eyelid color scoring as a measure of anemia, bottle jaw, body condition scoring, fecal soiling scoring and nose drainage for sheep or coat condition for goats), a farm can establish threshold levels at which actions should be taken. Fecal egg counting is another monitoring tool.
- When you determine deworming is needed, we must protect the efficacy of the chemical classes we have available. The American Consortium for Small Ruminant Parasite Control recommends strategies to best manage drug resistance. Animals should be dosed correctly by weighing animals on a scale or estimating weights with a tape before deworming. Goats need higher doses, so use appropriate deworming charts. Unless animals are very sick, restricting feed (overnight up to 24 hr) may intensify the effectiveness of dewormers. Rotating between drugs will not help prevent resistance, but using a combination of dewormer classes together at the full dose is extremely helpful. Repeat dosing is also effective with certain drug classes. I would encourage all producers to visit www.wormx.info for more information on proper deworming protocols as well as to view upcoming FAMACHA© certifications.
With no new dewormers being developed, producers should do everything possible to slow down the development of drug resistance. Combining a number of the methods discussed in this article will lead to a more effective parasite management program than relying on any one technique alone. Contact a knowledgeable veterinarian or our local Extension office to further discuss management strategies and work with a veterinarian to ensure proper use of deworming drugs.