Cypermethrin and Permethrin Ear Stips for Control of Lice on Beef Cattle, 1982

Experimental cattle were heifer calves of mixed breeds, and originated in eastern WY. Experimental groups of 9 animals each were housed in separate pens at Torrington, WY. Insecticidal ear strips were suspended from standard, identification tags by means of plastic straps. Each strap was placed through a hole near the bottom of the ear tag and through a hole in the end of the ear strip. Cypermethrin 7% or permethrin 10% strips were placed on both ears of the experimental animals. All strips were installed on Nov 25, ‘8’, following pretreatment lice counts. Total numbers of lice were recorded in inspection areas which were one 15-cm hair part on the poll and three 15-cm hair parts on the head, brisket, neck, backline and rumptail head. Viability of lice was determined post treatment by microscopic examination of specimens.