Evaluation of Three Formulations of Guardian 7.5% Ear Tags for Face Fly and Horn Fly Control on Beef Cattle, 1984

Abstract

Abstract Efficacy was evaluated Jun–Sep for face fly and horn fly control on beef cattle. Ectrin 8.0% ear tags and Permectrin 10.0% ear strips were evaluated for comparative efficacy. The following treatment groups were established on mixed-breed herds in Montgomery CO, VA: A) Guardian 7.5% ear tag (Formulation ‘A’), consisting of 20 cows, 20 calves, and one bull. Each animal received 2 ear tags, one in each ear, on 14 Jun. B) Guardian 7.5% ear tag (Formulation ‘B’), consisting of 40 heifers and 2 bulls. Each animal received 2 ear tags, one in each ear, on 15 Jun. C) Guardian 7.5% esir tag (Formulation ‘C’), consisting of 26 heifers and 10 steers. Each animal received 2 ear tags, 1 in each ear, on 15 Jun. The steers were later removed from pasture and only the heifers were used for evaluation. D) Ectrin 8.0% ear tag, consisting of 39 cows, 39 calves, and 1 bull. Each animal received 2 ear tags, 1 in each ear, on 14 Jun. E) Permectrin 10.0% ear strip, consisting of 21 cows, 21 calves, and 1 bull. Each animal received 2 ear strips, 1 in each ear, on 25 Jun. F) Untreated control, consisting of 21 cows and 16 calves. All test herds were maintained in separate pastures and all were situated within ca. 2 mi of each other. Weekly face fly and horn fly estimations were made by the same person on 10 adult animals per herd for 12 wk posttreatment. Numbers of face flies were estimated on the face and head and horn flies on one side of each animal. Pretreatment counts were made on all herds, except treatment E.