Sustainable Control of Gastro-intestinal Nematodes in Small Ruminants

Sustainable Control of Gastro-intestinal Nematodes in Small Ruminants

Summary

The Southern Consortium for Small Ruminant Parasite Control (SCSRPC) met twice in 2006, at Louisiana State University (LSU, May) and Fort Valley State University (FVSU, October) to review on-going and plan future SARE-related research and outreach activities. Over 2000 FAMACHA cards were sold at producer workshops held by consortium members throughout the southern USA and Puerto Rico in 2006. Sericea lespedeza (SL) hay was successfully pelleted and tested for efficacy against gastrointestinal nematodes (GIN) in both sheep (LSU) and goats (FVSU). Efficacy remained high against GIN of both species, with reduced fecal egg counts, improved blood packed cell volume, and reduced worm numbers in the abomasum. Additional trials with SL included a dose titration study comparing SL hay at 75, 50, and 25% of daily intake, and a growth trial comparing gains of parasitized and non-parasitized goats fed SL or bermudagrass (BG) hay. Anti-parasitic effects were maintained in animals fed SL at 50, but not 25% of the diet. Goats fed SL hay gained over 100 g/day compared with <80 g/day in the BG-fed animals. There was a synergistic effect between grazed SL and COWP on reducing GIN infection in sheep in a trial conducted at the USDA station in Arkansas. Forages containing condensed tannins (CT) were collected from throughout the southern USA, Puerto Rico, and the US Virgin Islands, and analyzed for CT content. In vitro testing of anti-parasitic activity of CT extracts from these forages was initiated. Several Scientific and producer-oriented papers were generated from the project in 2006. Hits on our project web site (SCSRPC.org) steadily increased each month.

Objectives/Performance Targets

1. Increase level of adoption of available sustainable GIN control strategies in the southeastern USA and PR by disseminating state-of-the-art knowledge and procedures, plus conduct cost-benefit analyses of these systems.
2. Investigate use of existing and developing 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.

Accomplishments/Milestones

Over 2000 FAMACHA cards for on-farm use were sold at producer workshops held by consortium members throughout the southern USA and Puerto Rico in 2006. Sericea lespedeza (SL) hay was successfully pelleted and tested for efficacy against gastrointestinal nematodes (GIN) in both sheep (LSU) and goats (FVSU). Additional trials with SL were successfully completed, including dose titration and growth trials with goats (FVSU), and grazing trials with sheep (USDA Research Station in Booneville, AR, and at an on-farm site in South Africa). The initial scientific papers on use of sericea lespedeza hay to control GIN infection in sheep and goats were published in the journal Veterinary Parasitology in 2006. Our group’s web site (SCSRPC.org) had over 10,000 hits in 2006.

Impacts and Contributions/Outcomes

The greatest impact of this work has been on increasing producer awareness of anthelmintic resistance as a major threat to profitable small ruminant production systems, which has led to greatly reduced use of the practice of ‘blanket’ regular deworming of all animals in the herd or flock. Due largely to SARE-funded activities of the Southern Consortium for Small Ruminant Parasite Control (SCSRPC), ‘targeted deworming’ of only those animals most in need of treatment has become commonplace with producers, not only with sheep and goats, but other species as well, such as llamas and alpacas. Reduced anthelmintic use is helping to preserve the efficacy of existing drugs, while saving producers money. This project has greatly increased awareness and adoption of alternative, non-chemical parasite control strategies, including use of copper oxide wire particles, grazing or feeding of condensed tannin-containing forages, and use of vaccines against Haemonchus contortus, a deadly blood-feeding parasite endemic to the southern USA, and other sub-tropical/tropical climates throughout the world. Increased interest and adoption of non-chemical parasite control techniques has been evident in that each year for the last 3 years, the number of requests for FAMACHA workshops and the number of FAMACHA cards sold for on-farm use has increased. Hits on our project web site have been increasing each month. Since the publication of the initial manuscripts on the anthelmintic potential of copper oxide wire particles and dried sericea lespedeza, the number of calls from producers, county extension agents, and other scientists requesting information on this technologies has been growing steadily. An indication of the impact of the sericea lespedeza work is that Sims Brothers Seed Company in Alabama, who has exclusive rights to market AUGrazer sericea lespedeza, a new, grazable type, sold old out all of their seed supply this year for the first time in many years. Another indication of the success of this work has been the expansion of the SCSRPC. We have been getting requests from scientists and extension specialists from institutions from all over the eastern and southern USA, Mexico, Europe, and Africa to join our Consortium. In our most recent SCSRPC research and extension planning meeting, held at Virginia Tech in May, 2007, we had nearly 30 participants from 15 different institutions.

Collaborators: