Sustainable Control of Gastro-intestinal Nematodes in Small Ruminants

Final Report for LS05-177

Project Type: Research and Education
Funds awarded in 2005: $250,000.00
Projected End Date: 12/31/2009
Region: Southern
State: Georgia
Principal Investigator:
Thomas Terrill
Fort Valley State University
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Project Information

Abstract:

Use of targeted deworming using the FAMACHA system to identify heavily parasitized sheep and goats greatly expanded over the last 4 years, with over 16,000 cards sold at producer workshops held in most of the states of the US, Puerto Rico, and the US Virgin Islands for on-farm use. Feeding of copper oxide wire particles (COWP) and grazing or feeding of dried sericea lespedeza were validated as highly effective novel anti-parasitic agents and have greatly increased in use by sheep and goat producers in the US, reducing their dependence upon chemical anthelmintics.

Project Objectives:

1. Increase level of adoption of sustainable GIN control strategies recently implemented in the southeastern USA and PR by broadly disseminating state-of-the-art knowledge and procedures.
2. Investigate use of novel non-chemical approaches for controlling GIN in small ruminants.
3. Develop and test sustainable small ruminant parasite control systems integrating conventional and novel GIN control strategies, conduct cost-benefit analyses, and assess the sustainability of these systems

Introduction:

Production of small ruminants is an important industry in the southern USA and Puerto Rico (PR). Low cost of entry and abundance of forage resources in these areas has made small ruminant production an attractive enterprise for small-scale and limited resource farmers. In addition, there is high demand for sheep and goat products in these regions (Glimp et al., 1986). The primary constraint to economic small ruminant production is reduced productivity and death losses, particularly of lambs and kids, due to infection with the blood-feeding gastrointestinal nematode (GIN) Haemonchus contortus. The conventional small ruminant GIN control method is preventive treatment of all the animals in a herd or flock with chemical anthelmintics, sometimes every 2-3 weeks (Miller, 1996). This treatment strategy greatly increases GIN selection for anthelmintic resistance in sheep and goats and has led to widespread resistance to drugs currently being used in the southern USA (Miller and Craig, 1996; Zajac and Gipson, 2000; Terrill et al., 2001; Mortensen et al., 2003). This problem is reaching epidemic proportions and is threatening the viability of small ruminant production in this region, particularly with limited resource farmers.
To address these problems, a team of researchers, extension specialists, and producers from FL, GA, LA, AR, the USVI, Denmark, and New Zealand held two SARE-funded planning workshops in 2001 (SARE Planning Grant LS01-124). Subsequently, a full SARE proposal was funded in 2002 (SARE R&E Grant LS02-143). That project was designed to gather information on anthelmintic use on sheep and goat farms, determine prevalence of anthelmintic resistance, and disseminate information to producers on strategic use of effective anthelmintics (“smart drenching”) and use of FAMACHA technology, which is a non-invasive means of assessing degree of anemia in small ruminants based upon eyelid color. Under the project just completed, this work continued in GA, FL, LA, AR, and PR, and was expanded into AL, OK, and VA. Scientists, Extension educators, and producers from each of these areas joined the current team for the new project.
Several promising novel, non-chemical control technologies were evaluated and validated as part of this project so that specific recommendations could be made to farmers for the most appropriate means to integrate these methods on the farm level. These technologies included use of nematode-trapping fungi (Larsen et al., 1996; 1997), copper oxide wire particles (COWP) (Bang et al., 1990; Burke et al., 2004), and dried or fresh forages containing condensed tannins (CT) (Min and Hart, 2003; Paolini et al., 2003; Shaik et al., 2006; Terrill et al., 2008). Additional work included breeding for parasite resistance through use of FAMACHA technology to identify GIN-resistant animals.
Our approach in this project was to educate and equip small ruminant producers and their advisors with the knowledge required to facilitate adoption of sustainable parasite control strategies that integrate conventional and novel GIN control technologies. This work impacted small-scale and limited resource farmers in the region by directing them toward sustainable practices which lower production costs, increase number of animals marketed, and enhance net profit.

Cooperators

Click linked name(s) to expand
  • Joan Burke
  • Ray Kaplan
  • James Miller
  • Elide Valencia
  • Mimi Williams

Research

Materials and methods:

Objective 1.

Over 16,000 FAMACHA cards have been sold for on-farm use in the US alone since ‘smart drenching’ and FAMACHA producer workshops were initiated during 2003. The on-farm adoption of the FAMACHA system was validated in sheep and goat herds in the southern US, Puerto Rico, and the US Virgin Islands as part of the recently-completed project.
More producer-oriented publications were added to the project web site (SCSRPC.org) over the last 4 years, and the web site traffic has continued to grow each year and now consistently has 60-70,000 hits per month.

Objective 2.

A series of experiments with confinement-fed and grazing sheep and goats were completed at collaborating institutions as part of this project to evaluate efficacy of copper oxide wire particles (COWP) in bolus form and added to feed pellets, a natural vaccine against Haemonchus contortus, and fresh (grazed) and dried (hay, leaf meal, pellets) sericea lespedeza, a high-tannin legume. For the COWP feed studies, the particles were milled into a complete pelleted 16% protein ration and compared with pellets with no COWP. The sheep and goats consumed the COWP feed pellets from automatic feeders over a 24-hr period. Fecal and blood samples were taken weekly for 28 days to determine effects on fecal egg count (FEC) and packed cell volume (PCV), respectively, and adult gastrointestinal nematodes (GIN) from the abomasum and small intestines were recovered, counted, and identified to species at the end of each trial. Other COWP studies included ewes with nursing lambs, and dose titration studies with lambs and kids. The vaccine studies were completed with parasitized goats given several doses of antigens developed from recovering and grinding adult Haemonchus contortus worms from the abomasum of GIN-infected animals. A series of studies with sheep were completed in which parasitized animals grazed sericea lespedeza paddocks only, a non-sericea paddock (grass), and a combination of grass and lespedeza, with FAMACHA readings, body condition scoring, FEC, and PCV samples taken every 2 weeks throughout the grazing season. Several experiments were completed with parasitized goats fed sericea lespedeza hay in ground (whole plant, leaf meal) and pelleted forms. A dose-titration study with fed ground whole plant sericea at 0, 25, 50, and 75% of the diet was also completed.

Objective 3.

Projects related to objective 3 included testing producer adoption of the FAMACHA system on sheep and goat farms in the US, Puerto Rico, and the US Virgin Islands, and evaluation of GIN control systems using combinations of FAMACHA, COWP, and sericea lespedeza grazing compared with conventional anthelmintic-based systems for small ruminant GIN control. For the FAMACHA producer adoption work, farmers monitored sheep and goats using FAMACHA over several grazing seasons, with their results compared with data generated during monthly visits by FAMACHA-trained scientists and research technicians. For the novel control systems work, cost estimates for novel versus conventional control methods were made to allow some projections on economic impact of reduced use of anthelmitic drugs.

Research results and discussion:

The FAMACHA system has been a major success story for the Southern Consortium for Small Ruminant Parasite Control, with over 16,000 cards sold at 2-300 workshops throughout the US, Puerto Rico, and the US Virgin Islands. Producers adopt the system very readily, reducing their deworming frequency by up to 90% while improving herd or flock genetics by culling animals identified as GIN-susceptible. Both outcomes have been routinely reported by users of this technology. Quantifying these impacts on sheep and goat producers is currently underway through regional and national survey instruments. These data will be processed and the results made available on our Consortium web site over the next year.

The vaccine work showed this strategy to be effective against Haemonchus contortus infection in grazing goats, but the natural antigen is too expensive to be made commercially available to producers. This will depend upon the development of a recombinant product, but so far, efforts to do this by other research groups has not been successful. More practical and much cheaper non-chemical GIN control options included the use of COWP and grazed or dried sericea lespedeza fed in ground or pelleted forms. The trials with COWP boluses and feed pellets showed high anti-parasitic activity against H. contortus (up to 95% control) in both lambs and kids. We found more variable, but still positive results with older animals. In systems work, use of COWP to control GIN infection in lambs was as effective as Levamisole at a fraction of the cost (8-10 cents per dose). For the sericea lespedeza work, all grazing studies we have completed have shown a consistent effect of rapidly reducing FEC in sheep up to 80%. Grazing trials with goats are currently underway, but similar results are expected because the anti-parasitic effects of sericea in dried forms (ground whole plant, leaf meal, pellets) fed to goats have been consistently positive (60-80% reduction in FEC, 50-70% reduction in adult H. contortus).

Participation Summary

Educational & Outreach Activities

Participation Summary

Education/outreach description:

Refereed Journal Manuscripts

Terrill, T.H., G.S. Dykes, S.A. Shaik, J.E. Miller, B. Kouakou, G. Kannan, J.M. Burke, and J.A. Mosjidis. 2009. Efficacy of sericea lespedeza as a natural dewormer in goats: dose titration study. Veterinary Parasitology 163:52-56.

Moore, D., T.H. Terrill, B. Kuakou, S.A, Shaik, J.A.Mosjidis, J.E. Miller, M.Vanguru and G. Kannan. 2008. The effects of feeding sericea lespedeza on growth of goats naturally infected with gastrointestinal nematodes. Journal of Animal Science 86:2328-2337.

Terrill, T.H., J.A. Mosjidis, D.A. Moore, S.A. Shaik, J.E. Miller, J.M. Burke, J.P. Muir, and R.Wolfe. 2007. Effect of pelleting on efficacy of sericea lespedeza hay as a natural dewormer in goats. Veterinary Parasitology 146:117-122.

Kaplan, R.M., A.N. Vidyashankar, S.B. Howell, J.M. Neiss, L.H. Williamson, and T.H. Terrill. 2007. A novel approach for combining the use of in vitro and in vivo data to measure and detect emerging moxidectin resistance in gastrointestinal nematodes of goats. International Journal for Parasitology 37:795-804.

Burke, J.M., D. Morrical, and J.E. Miller. 2007. Control of gastrointestinal nematodes with copper oxide wire particles in a flock of lactating polypay ewes and offspring in Iowa, USA. Veterinary Parasitology 146:372-375.

Burke, J.M, T.H. Terrill, R.R. Kallu, J. E. Miller, and J. Mosjidis. 2007. Use of copper oxide wire particles to control gastrointestinal nematodes in goats. Journal of Animal Science 85:2753-2761.

Burke, J.M., R.M. Kaplan, J.E. Miller, T.H. Terrill, W.R. Getz, S. Mobini, E. Valencia, M.J. Williams, L.H. Williamson, and A.F. Vatta. 2007. Accuracy of the FAMACHA system for on-farm use by sheep and goat producers in the southeastern United States. Veterinary Parasitology 47:89-95.

Shaik, S.A., T.H. Terrill, J.E. Miller, B. Kouakou, G. Kannan, R. M. Kaplan, J.M. Burke, and J. Mosjidis. 2006. Sericea lespedeza hay as a natural deworming agent against gastrointestinal nematode infection in goats. Veterinary Parasitology 139:150-157.

Lange, K.C., D.D. Olcott, J.E. Miller, J.A. Mosjidis, T.H. Terrill, J.M. Burke, and M.T. Kearney. 2006. Effect of sericea lespedeza, fed as hay, on natural and experimental Haemonchus contortus infections in lambs. Veterinary Parasitology 141, 273-278.

Burke, J.M., and J.E. Miller. 2006. Evaluation of multiple low doses of copper oxide wire particles compared with levamisole for control of Haemonchus contortus in lambs. Veterinary Parasitology 139:145-149.

Burke, J.M., and J.E. Miller. 2006. Control of Haemonchus contortus in goats with a sustained-release multi-trace element/vitamin ruminal bolus containing copper. Veterinary Parasitology 141:132-137.

Bath, G.F. 2006. Practical implementation of holistic internal parasite management in sheep. Small Ruminant Research 62:13-18.

Burke, J.M., J.E. Miller, M. Larsen, and T.H. Terrill. 2005. Interaction between copper oxide wire particles and Duddingtonia flagrans in lambs. Veterinary Parasitology 134:141-146.

Burke, J.M., J.E. Miller, and D.K. Brauer. 2005. The effectiveness of copper oxide wire particles as an anthelmintic in pregnant ewes and safety to offspring. Veterinary Parasitology 131:291-297.

Papers Published in Conference Proceedings

Terrill, T.H. 2008. Sericea lespedeza: a natural dewormer for sheep and goats. Proceedings of the XXI International Grassland Congress, 26 June – 6 July, 2008, Hohhot, China.

Moore, D.A., T.H. Terrill, B. Kouakou, S.A. Shaik, J.A. Mosjidis, J.E. Miller, M. Vanguru, G. Kannan, and J.M. Burke. 2007. The effects of feeding sericea lespedeza hay on growth rate of goats naturally infected with gastrointestinal nematodes. Proceedings of the American Forage and Grassland Council 16, 137-140.

Dykes, G.S., Terrill, T.H., Shaik, S.A., Miller, J.E., Kouakou, B., Kannan, G., Burke, J.M., Kaplan, R.M., Mosjidis, J.A., 2006. Effect of sericea lespedeza hay on gastrointestinal nematode infection in goats. Proceedings of the American Forage and Grassland Council 15: 245-249.

Shaik, S.A., T.H. Terrill, J.E. Miller, B. Kouakou, G. Kannan, R.M. Kaplan, J.M. Burke, and J.A. Mosjidis. 2005. Anthelmintic effects of sericea lespedeza hay fed to goats infected with Haemonchus contortus. Proceedings of the XX International Grassland Congress, 26 June – 6 July, 2005, Dublin, Ireland.

Miller, J.E., J.A. Stuedemann, and T.H. Terrill. 2005. Nematode parasites and grazing research. Proceedings of the 59th Southern Pasture and Forage Crop Improvement Conference, 11-13 May 2005, Philadelphia, MS.

Terrill, T.H., and J.E. Miller. 2005. Nematode parasites in small ruminant grazing research: Changing perspectives. Proceedings of the 59th Southern Pasture and Forage Crop Improvement Conference, 11-13 May 2005, Philadelphia, MS.

Producer-oriented Publications

Burke, J.M, J.E. Miller, and T.H. Terrill. 2007. Use of copper oxide wire particles (COWP) to control barber pole worm in lambs and kids. www.scsrpc.org.

Coffey, L., M. Hale, T. Terrill, J. Mosjidis, J. Miller, and J. Burke. 2007. Tools for managing internal parasites in small ruminants: sericea lespedeza. NCAT/ATTRA and Southern Consortium for Small Ruminant Parasite Control, www.scsrpc.org.

Hale, M, J. Burke, J. Miller, and T. Terrill. 2007. Tools for managing internal parasites in small ruminants: copper wire particles. NCAT/ATTRA and Southern Consortium for Small Ruminant Parasite Control, www.scsrpc.org.

Shaik, A.S., and T.H. Terrill. 2005. “Sericea lespedeza hay: Ready to accept the challenge from Haemonchus contortus.” Georgia Small Ruminant Research and Extension Center Newsletter, Winter 2005.

Theses

Moore, D.A. 2007. The effects of feeding sericea lespedeza hay on the growth rate of animals naturally infected with gastrointestinal nematodes. Master’s thesis. Animal Science Master’s Program, Fort Valley State University, Fort Valley, GA.

Soli, F. 2008. Efficacy of copper oxide wire particles against gastrointestinal nematode infection in sheep and goats. Master’s thesis. Animal Science Master’s Program, Fort Valley State University, Fort Valley, GA.

Project Outcomes

Project outcomes:

The greatest impact of this work has been on increasing sustainability of small ruminant production in the USA, Puerto Rico, and the US Virgin Islands by reducing use of and dependence on chemical dewormers through the use of the FAMACHA system. This simple card, developed in South Africa, has allowed thousands of US farmers to reduce anthelmintic expenditures by approximately 80%, while improving herd and flock genetics for resistance to parasitic infection. Since the publication of our first paper showing the anti-parasitic potential of sericea lespedeza (SL) hay, there has been a tremendous resurgence of interest in this plant (also known as poor man’s alfalfa) as a low-input hay and pasture crop and natural anthelmintic for all classes of livestock. Many of the GIN control methods that have been tested and proven successful with goats and sheep as part of this project, including FAMACHA, SL hay, and copper oxide wire particles, are now being used to control parasites in other ruminant species, including llamas and alpacas, beef and dairy cattle, and exotic species, such as giraffes and other animals in zoological parks.

Economic Analysis

Preliminary economic analysis suggests that producers implementing the FAMACHA system can reduce their drug costs by up to 80% or more while potentially improving herd or flock genetics for resistance. Exact dollar amounts are difficult to assess due to widely variable drug costs. However, using Cydectin sheep drench as an example, which costs approximately $1.00 per treatment per animal (goat dose), if a producer with 100 breeding does normally deworms 4 x per year, his drug costs for the doe herd alone would be $400.00 per year. Through using the FAMACHA system, his anthelmintic costs could be reduced by $320.00 per year or more. If producers used the combination of FAMACHA and COWP at the 2 g dose (10 cents/g) to deworm their animals, savings per year would be $384.00.

Farmer Adoption

Producers have readily adopted the FAMACHA system for use on-farm, and more than 16,000 of the FAMACHA cards have been sold ($10.00/card) at hundreds of training workshops throughout the US, Puerto Rico, and the US Virgin Islands. A growing number of producers are now making their own COWP boluses for treating goats and sheep by repackaging the commercially-available form (25 g boluses for use in cattle) into small gel capsules. Email and phone requests on the use of COWP and sources of hay and seeds of sericea lespedeza continue to increase each year, and hits on our Consortium web site continue to grow (avg. 60-70,00 hits per month).

Recommendations:

Areas needing additional study

The main areas needing additional study include more in depth analysis of the economic impact of producer adoption of the FAMACHA system, the use of copper oxide wire particles (COWP), and dried or grazed sericea lespedeza (SL) to control small ruminant GIN. Additional research is needed concerning the mechanism of action of COWP and SL against specific life stages of GIN to allow efficient combination of these technologies with other non-chemical control techniques (breeding for resistance, vaccines, nematode-trapping fungi) and FAMACHA with conventional and organic sheep and goat farming systems.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.