Submitted to: Veterinary Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/14/2007
Publication Date: 4/11/2007
Citation: Burke, J.M., Morrical, D., Miller, J.E. 2007. Control of gastrointestinal nematodes with copper oxide wire particles in a flock of lactating Polypay ewes and offspring in Iowa. Veterinary Parasitology. 146(3-4):372-375.
Interpretive Summary: Widespread resistance of gastrointestinal worms to chemical dewormers has led to the need for alternative parasite control. Copper oxide wire particles (COWP) have been used as an alternative to chemical dewormers in hair sheep in the U.S., but its use and safety in wool sheep has not been examined extensively. Scientists at USDA, ARS in Booneville, AR, Iowa State University, and Louisiana State University determined that COWP can effectively and safely control Haemonchus contortus in wool lambs, but other means may be necessary in mature ewes. These results indicate that COWP may aid in control of gastrointestinal parasites and this information is important to producers, extension agents, and scientists.
Technical Abstract: Copper oxide wire particles (COWP) have been used in lambs to reduce infection of Haemonchus contortus in hair breed lambs in the southeastern U.S. without signs of copper toxicity. However, copper sensitivity among breeds and regions varies. The objective was to determine the effectiveness and safety of COWP in lactating Polypay ewes and their offspring grazing alfalfa/bluegrass pasture in a rotational grazing system. Mature Polypay ewes were administered 0, 0.5 g, 1 g, or 2 g (n = 8 or 9/dose) COWP approximately 60 days after lambing in mid-July 2005. Their offspring were administered 0 (n = 6), 0.5 or 0.75 g (n = 9), 1 or 2 g (n = 6) COWP at two months of age in late July. The primary gastrointestinal nematode was H. contortus (70%). Between Days 7 and 35 FEC were greater in 0 and 0.5 g COWP groups compared with ewes administered 2 g COWP (COWP x day, P < 0.004). PCV decreased in all groups of ewes between Days 0 and 21 (day, P < 0.001). Aspartate aminotransferase (AST) activity, a measure of liver copper levels, and body weight was similar among groups of ewes. FEC decreased within 7 days in COWP-treated compared with untreated lambs and remained low throughout experiment (COWP x day, P < 0.05). PCV increased in COWP-treated lambs between Days 7 and 35 and decreased in untreated lambs between Days 0 and 21 (COWP x day, P < 0.009). AST activity was similar among groups of lambs. Administration of 2 g COWP to ewes prevented a rise in FEC, but a dose of 0.5 g was ineffective as an anthelmintic. Administration of all doses of COWP to lambs decreased FEC and increased PCV compared to untreated lambs. There were no signs of copper toxicity in ewes or lambs. Alternative management of ewes for H. contortus may be necessary, but COWP was effective in H. contortus management for lambs.