Evaluation of Ivomec Pour-On for the Control of Horn Flies in West Central Nebraska, 1993

Abstract

Abstract Ivomec® pour-on was evaluated in two studies at two different locations in West Central Nebraska. In study No. 1, Ivomec was applied to 72 yearling steers located at the Gudmundsen Sandhills Laboratory, Whitman, NE. The steers were weighed and the Ivomec was applied at the recommended rate. A second application was made 28 d later, 7 Jul. A group of 44 cows served as an untreated control. In study No. 2, Ivomec pour-on was compared to 1% Co-Ral dust bags (force-use, to obtain water) for horn fly control. This study was located near North Platte, NE, in native range. Ivomec was first applied to 41 heifers 27 May at the recommended rate and subsequent applications were made about every 28 d until the end of the study. Treatment dates were 27 May, 30 June, and 4 Aug. Eighty heifers utilized the 1% Co-Ral dust bags and a group of 10 cows served as an untreated control. Horn fly counts for both studies were recorded at weekly intervals by counting the total number of horn flies on both sides on an animal.