Submitted to: Veterinary Parasitology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 7/1/2005
Publication Date: 11/1/2005
Citation: Burke, J.M., Miller, J.E., Larsen, M., Terrill, T.H. 2005. Interaction between copper oxide wire particles and Duddingtonia flagrans in lambs. Veterinary Parasitology. 134:141-146. Interpretive Summary: Widespread resistance of gastrointestinal worms to chemical dewormers has led to the need for alternative parasite control. Copper oxide wire particles (COWP) and the nematode-trapping fungus Duddingtonia flagrans have been used as alternative controls for gastrointestinal parasites in sheep, but not concurrently. There was no adverse effect of COWP on the ability of the fungus to trap residual larvae after COWP treatment and a beneficial effect to lambs receiving both treatments. These results indicate that COWP and D. flagrans are a sustainable means of controlling parasites on pasture and this information is important to producers, extension agents, and scientists.
Technical Abstract: The objective of the experiment was to determine if copper oxide wire particles (COWP) had any effect on the activity of the nematode-trapping fungus Duddingtonia flagrans in growing lambs. COWP has been used recently as an anthelmintic in small ruminants because of nematode resistance to chemical dewormers. D. flagrans has been used to control free-living stages of parasitic nematodes in livestock. Katahdin and Dorper lambs, 4 months of age, were administered 0 or 4 (n = 24/dose) g COWP in early October 2003. Haemonchus contortus was the predominant gastrointestinal parasite during the trial. Half the lambs from each COWP group were supplemented with corn/soybean meal with or without D. flagrans for 35 days. Fecal egg counts (FEC) and packed cell volume (PCV) were determined weekly between Days 0 (day of COWP administration) and 35. Feces from each of the four treatment groups were pooled and three replicates were cultured for 14 days at room temperature. L3 larvae were identified and counted per g of feces cultured. Weight gains were minimal during the 35 day trial and were similar among treatment groups. COWP decreased FEC from more than 5,000 eggs/g (epg) to 250 epg within 7 days and FEC remained lower than lambs not treated with COWP. FEC of lambs fed fungus without COWP were lower on Days 7 and 14 than those not fed fungus. PCV of COWP-treated lambs was greater than those not treated between Days 14 and 35. Number of larvae hatched was decreased in feces from lambs treated with COWP and D. flagrans between Days 14 and 35. Percentage of larvae identified as H. contortus decreased in feces collected from lambs treated with COWP and D. flagrans between Days 14 and 28 compared with other treatments. Other trichostrongyles were present and remained less than 7% in feces collected from control lambs. There was no adverse effect of COWP on the ability of D. flagrans to trap residual larvae after COWP treatment. There was a beneficial effect of treating lambs with both COWP and fungus. Fewer eggs hatched leads to fewer larvae on pasture.