Controlling Internal Parasites in Small Ruminants Sheep & Goat Toolbox Small ruminant overview Goats • • • • Prefer to browse Selective eaters Like to roam Can handle some toxins other livestock can’t • Like variety Sheep • Prefer to graze close to the ground • Like to roam • Enjoy many weeds Introduction to parasites • Biggest concern for small ruminant producers • Costly – Treatment costs – Reduced animal performance – Death • Parasites have developed resistance to dewormers • Parasites can be managed We cause problems • We force them to eat close to the ground • We crowd them • We cause parasite resistance – Deworming too often and incorrectly • We create environments where parasites thrive • We don’t keep them in good enough condition • We “baby” our animals – keep animals that we should cull The problem: parasites Photos courtesy of Dr. Jean Marie Luginbuhl, North Carolina State University Primary parasites • Barberpole worm – Haemonchus contortus • Brown stomach worm – Telodorsagia (Ostertagia) circumcincta Picture from www.sheepandgoat.com • Bankrupt worm – Trichostrongylus colubriformis • Coccidia – Eimera sp. Diagram from www.sheepandgoat.com Parasite life cycle • Parasite larvae ingested • Adults make residence in the body • Adults lay eggs • Eggs passed in feces • Eggs hatch and larvae crawl up blades of grass • Animals ingest larvae (repeat cycle) Diagram from www.sheepandgoat.com Parasitism • Practically inevitable • Should be managed so that parasitism is not evident • Young animals most affected • Does/ewes affected last month of pregnancy & around kidding/lambing Signs of parasitism • • • • Loss of condition Rough hair coat Bottle jaw Low energy Signs of parasitism (cont.) • Pale mucous membranes – Indicates anemia • Scours, diarrhea • Death We cannot rely on drugs alone! • Parasites are becoming resistant to drugs – Particularly sheep & goats • Parasites are already becoming resistant to the newest anthelmintic drugs • We are running out of drugs! • Anthelmintics should not be overused – Increases resistance • Other methods must be used in conjunction with anthelmintics Causes of resistance • Frequent deworming – No dewormer is 100% effective, 100% of the time – Frequent deworming increases the rate resistance develops • Deworming all animals, regardless of need – Increases rate of resistance – Costs more $$$$$ • Under dosing – Leaves more of the strong worms • Deworming and moving to a clean pasture What do we do? • Pasture management – Sanitation – Avoid over-grazing • • • • • Animal management Animal selection FAMACHA© Smart Drenching Other techniques Pasture management • Should be the primary technique • Monitor Forage Height – Research indicates that most larvae can only travel about 2 inches off the ground – Grazing close to the ground increases parasite ingestion Pictures from www.sheepandgoat.com Pasture management • Stocking Rate • Overstocking causes: – More worm deposits – Animals forced to graze close to manure • Multi-species Grazing – Small ruminants, cows, and horses do not share the same parasites • Haying – Removes & exposes larvae to the sun Animal management • Immune System – Healthier animals have fewer problems – Provide good nutrition • Select resistant animals – Select a resistant buck/ram – Select resistant breeds Picture from: ansi.okstate.edu Provided by Dr. An Peischel • Goats: Spanish, Myotonic, Kiko, not Boer • Sheep: Hair Sheep, Florida Native • Cull – Animals needing more treatment – Animals depositing a lot of eggs (FEC) General management • Sanitation – Keep feeders and water free of feces – Keep areas where animals congregate as clean as possible • Carefully chose, isolate, and de-worm new animals FAMACHA© Classifies animals based on level of anemia 1-5 scale • 1-not anemic • 5-anemic Treat 4’s and 5’s Sometimes 3’s Photo from www.sheepandgoat.com FAMACHA© • Must be trained by a veterinarian • Keep records • Cull animals repeatedly treated • Treat less, save money! Smart Drenching • Find out which dewormers work – Talk to your local veterinarian • Weigh animals prior to deworming – Don’t under-dose • Deliver dewormer over the tongue, in the back of the throat • Withhold feed 12 to 24 hours prior • De-worm only animals that need it! Photo from http://bedford.extension.psu.edu Other techniques: copper wire • Copper oxide wire particles (COWP) have been proven to be an effective method of controlling H. contortus (barber pole worms) in sheep & goats • COWP can be an effective component of a holistic parasite management strategy. • Should not be the only method of parasite management http://animetal.com.tr How to use COWP • Purchase copper boluses – Copasure©, available in 12.5 g and 25 g boluses • Obtain smaller gel capsules – Available at your local pharmacy or health food store, also available from veterinary supply at times. • Repackage cattle bolus into smaller gel capsule to make 0.5g dose – Size 1 gelatin capsules filled1/3 full – Size 3 capsules filled 3/4 full • Administer bolus with a pill gun designed for pets or wooden dowel with PVC pipe How it works Copper oxide wire particles • Animals should receive no more than • Four (if 0.5 or 1 g is used) or • Two (if 2 or 4 g is used) Per worm season • Effective in reducing abomasal (H. contortus) worms only and not intestinal worms. • COWP should not be the only method used for controlling internal parasites. Other techniques: condensed tannins • Effects of tannins vary depending on type, concentration, and the animal consuming the tannins. • Potential positive effects: – Increase in by-pass protein – Reduction in bloating, increased milk production – Reduction in internal parasite numbers, egg output, & hatchability. • Potential negative effects: – Reduced intake and reduced digestibility, leading to a decline in animal productivity. – Negative effects are seen more often when CT concentration is high (above 55 g CT/kg DM in the forage) Other techniques: condensed tannins Condensed tannin (CT) content in different forage species.* (Adapted from Min and Hart, 2003 and Min et al., 2005). Forage CT, g/kg of DM %DM Birdsfoot trefoil 48 4.8 Big trefoil 77 7.7 Sanfoin 29 2.9 51-84 5.1-8.4 0.5 .05 Sericea lespedeza 46-152 4.6-15.2 Perennial ryegrass 1.8 0.18 Chicory 3.1 0.31 Crabgrass/tall fescue mixture 3.2 0.32 Sulla Lucerne (alfalfa) *The standard used for analysis will affect the results. For these studies, a Quebracho standard was used. Condensed tannins: Sericea lespedeza • High-tannin forage • Scientifically proven to reduce parasite loads in sheep and goats. • Research has shown that Sericea is effective against internal parasites when grazed or when fed in dried forms, such as hay or pellets. Other techniques • Garlic • Nematode-trapping Fungus – Fungus traps parasite larva in the feces – Not commercially available yet • Vaccines – Not available yet Conclusion • Parasites are the biggest problem for sheep and goat producers • No technique is 100% effective • Several techniques should be used • Select for resistant animals • Do not over-treat (causes resistance!) http://www.flickr.com/photos/mikeboehmer/147 0921528/in/set-72157602227248322/ For more information • See ATTRA publications at www.attra.ncat.org • Managing Internal Parasites • “Tools for Managing” series: • Copper Wire • Sericea Lespedeza • Animal Selection • Pasture Management • American Consortium for Small Ruminant Parasite Control at www.acsrpc.org The National Center for Appropriate Technology (NCAT) is a nonprofit organization that helps people and communities. NCAT champions smallscale, sustainable and local solutions to reduce poverty, protect communities and promote natural resources. Since 1976, NCAT has weatherized houses, trained farmers, monitored energy use and demonstrated renewable technology. NCAT works on local and national projects that foster a healthy quality of life for everyone.