Evaluation of Max-Con® and Optimizer® Ear Tags Applied at 2 Tags Per Animal for Control of Cattle Lice in Wyoming, 1992

The experiment was performed with 1-yr-old heifer and steer calves at Laramie, WY, and with 2-yr-old steers at Torrington, WY. Average weights of the animals were 211 and 467 kg, respectively. At Laramie, the cattle were heavily infested with Bovicola bovis. At Torrington, Linognathus vituli, Haematopinus eurysternus and Solenopotes capillatus were the dominant species. Cattle were housed in separate pens in groups of five at both locations. Cattle were ranked according to lice density, and similarly infested cattle were then randomly assigned to one of three treatment groups. Five animals per treatment were used in the study at Laramie and 15 per treatment at Torrington. Hair was parted and lice density was estimated by observing and recording the numbers of lice of each species at sample sites on selected body regions of the host. Body regions examined were; one 5 x 15 cm area on the topline; one 5 x 15 cm area on the withers; two 10 X 15 cm areas surrounding the right and left eyes; two 5 x 10 cm areas on the right and left cheeks; one 5 x 25 cm area on the muzzle; and one 5 x 15 cm area on the dewlap. Each animal was tagged in both ears. Cattle at Torrington were tagged on 27 Dec, and cattle at Laramie were tagged on 19 Feb.