Experiences with integrated concepts for the control of Haemonchus contortus in sheep and goats in the United States

Authors: TERRILL, T - Fort Valley State University; MILLER, J - Louisana State University; Burke, Joan; MOSJIDIS, J - Auburn University

Submitted to: Veterinary Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/12/2011
Publication Date: 3/1/2012
Citation: Terrill, T.H., Miller, J.E., Burke, J.M., Mosjidis, J.A. 2012. Experiences with integrated concepts for the control of Haemonchus contortus in sheep and goats in the United States. Veterinary Parasitology. 186:28-37.

Interpretive Summary: Small ruminant production is a growing industry in the southeastern U.S., but the industry has been plagued by drug resistant internal parasites, which cause the most challenging health issues for these animals. Alternatives to chemical anthelmintics have been studied by scientists at Fort Valley State University in GA, USDA, ARS in Booneville, AR, Louisiana State University, and Auburn University in AL. These methods have been reviewed and include the use of copper oxide wire particles (COWP) as a dewormer, feeding or grazing the condensed tannin-rich forage, sericea lespedeza to reduce parasites, and the use of the FAMACHA system as a tool for selective treatment of animals. This information will be presented to parasitologists from around the world and will be disseminated to veterinarians and animal specialists to aid in producer decisions.

Technical Abstract: The generally warm, moist environmental conditions in the southern United States (U.S.) are ideal for survival and growth of the egg and larval stages of Haemonchus contortus and other gastrointestinal nematodes (GIN) of sheep and goats, and GIN infection is the greatest threat to economic small ruminant production in this region. With anthelmintic resistance now reaching epidemic proportions in small ruminants in the U.S., non-chemical control alternatives are critically needed. The Southern Consortium for Small Ruminant Parasite Control (SCSRPC) was formed in response to this crisis and over the last decade has successfully validated the use of several novel control technologies, including copper oxide wire particles (COWP), nematode-trapping fungi, and grazing or feeding hay of the high-tannin perennial legume sericea lespedeza (Lespedeza cuneata). Thanks to the efforts of this group and others in the U.S., producer attitudes toward GIN control have been shifting away from exclusive dependence upon anthelmintics towards more sustainable, integrated systems of parasite control. Some novel control technologies have been readily adopted by producers in combination with appropriate diagnostic tools, such as FAMACHA©. Others techniques are still being developed, with producer adoption awaiting commercialization. Although new drugs will likely be available to U.S. goat and sheep producers in the future, these will also be subject to development of anthelmintic resistance, so it is unlikely that farmers will abandon sustainable GIN control principles. With emerging markets for grass-fed or organic livestock, there will continue to be a critical need for research and outreach on development and on-farm application of integrated GIN control systems for small (and large) ruminants in the U.S. for the foreseeable future.