ARS | Publication request: Coprological evaluation of pour-on and injectable formulation of moxidectin in beef cattle

Submitted to: American Association of Veterinary Parasitologists Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: July 6, 2010
Publication Date: July 30, 2010
Citation: Powell, J.G., Gunter, S.A., Tucker, C.A., Reynolds, J.L., Johnson, Z.B. Coprological evaluation of pour-on and injectable formulation of moxidectin in beef cattle. American Association of Veterinary Parasitologists Proceedings. Atlanta, GA. 85:77-78.

Technical Abstract: Two, 28 day(d) studies were conducted with naturally infected beef calves to assess the effect of allo-grooming behavior on fecal egg count (FEG)reductions and coproculture counts following treatment with pour-on or injectable moxidectin. The first study was conducted at the USDA Southern Plains Experimental Range near Ft. Supply, OK with 137 steers (initial Body Weight(BW)=253±19 kg), and the second study was conducted at the University of Arkansas Stocker Cattle Unit in Fayetteville, AR with 80 steers (initial BW=226±38kg). Calves at both locations were allocated to one of three treatments: injectable moxidectin, pour-on moxidectin, and a negative control. Calves were also assigned to one of five different pasture arrangements consisting of: 1) control calves only, 2) injectable calves only, 3) pour-on calves only, 4) pour-on and control calves, and 5) injectable and control calves. At the Oklahoma location, stocking rate was 1hd/1.25ha, and 1hd/0.15ha at the Arkansas location. At each respective location, fecal egg and coproculture counts were similar between groups on d 0; however, a difference existed for location effect (P<0.0001), indicating cattle at the Arkansas location exhibited higher FEC on days 0, 14 and 28 compared to calves at the Oklahoma location. Results indicate that control calves pastured with pour-on treated calves did not exhibit reduction in FEC from possible allo-grooming at either location. However, at both locations, regardless of pasture assignment, FEC were lowest (P<0.05) in pour-on calves, intermediate in injectable calves and highest in untreated calves on days 14 and 28. At both locations, 28d post-treatment, calves that were treated with moxidectin exhibited higher (P<0.05) percentages of L3 as Cooperia compared to control calves. Percentages of L3 as Trichostrongylus and Ostertagia were similar among treated and control calves