Interaction between copper oxide wire particles and Duddingtonia flagrans in lambs J.M. Burke a, * , J.E. Miller b,c,d , M. Larsen e , T.H. Terrill f a Dale Bumpers Small Farms Research Center, USDA, ARS, Booneville, AR 72927, USA b Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA c Department of Animal Science, Louisiana State University, Baton Rouge, LA 70803, USA d Department of Veterinary Science, Louisiana State University, Baton Rouge, LA 70803, USA e Danish Center for Experimental Parasitology, Section for Parasitology, Department of Veterinary Pathobiology, Royal Veterinary and Agricultural University, DK-1870 Frederiksberg C, Denmark f College of Agriculture, Home Economics and Allied Programs, Agricultural Research Station, Fort Valley State University, Fort Valley, GA 31030, USA Received 1 February 2005; received in revised form 16 June 2005; accepted 16 June 2005 Abstract An experiment was completed 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 a dewormer in small ruminants because of nematode resistance to anthelmintics. 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 no or 4 g COWP (n = 24/dose) in early October 2003. Haemonchus contortus was the predominant gastrointestinal parasite during the trial, which was acquired naturally from pasture. 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 lambs in each treatment group were pooled and three replicates per group were cultured for 14 days at room temperature. Larvae (L3) were identified and counted per gram of feces cultured. Treatment with COWP was effective in decreasing FEC, which remained low compared with FEC from lambs not treated with COWP. This led to an increase in PCV in these lambs (COWP  day, P < 0.001). Number of larvae was decreased in feces from lambs treated with COWP and D. flagrans between days 14 and 35 compared to the other groups of lambs (COWP  D. flagrans  day, P < 0.003). 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 (COWP  D. flagrans  day, P < 0.05). Other trichos- trongyles 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. With fewer eggs being excreted due to the effect of copper on H. contortus, and the additional larval reducing effect exerted by the nematode destroying fungus D. flagrans, the www.elsevier.com/locate/vetpar Veterinary Parasitology 134 (2005) 141–146 * Corresponding author. Tel.: +1 479 675 3834; fax: +1 479 675 2940. E-mail address: jmburke@spa.ars.usda.gov (J.M. Burke). 0304-4017/$ – see front matter. Published by Elsevier B.V. doi:10.1016/j.vetpar.2005.06.018