Evaluation of Amitraz Collars and Pour-On Applications of Young'S® Poron 20, GX-118™, and Dursban® 44 for Lice Control on Beef Cattle, 1986

Abstract

Abstract Experimental steer and heifer calves were of mixed breeds and originated in eastern WY. They were housed in separate pens in groups of 7 animals each at Torrington, WY. The cattle were naturally infested with the cattle biting louse, Bovicola bovis, the longnosed cattle louse, Linognathus vituli, and the little blue cattle louse, Solenopotes capillatus Enderlein. Lice density was estimated by observing and recording the number of each species at sample sites on the host. One 15-cm sample site was located across the occipital area directly behind the poll. The equivalent of 3, 15-cm sample sites were located on the head, shoulder, and topline. Sample sites on the head were 1, 15-cm hairpart on either side of the face from the corner of the mouth toward the base of the ear and 2, 7.5-cm hairparts on either side of the muzzle. Sample sites on the shoulder were 3, 15-cm vertical parts on the right side of the body. Sample sites on the topline were located on the right side of the animal ca. 25 cm posterior to the withers and 25 cm anterior to the hip bone. These sites consisted of 3 vertical 15-cm hairparts ca. 15 cm apart. For the evaluation of amitraz collars and Dursban 44 pour-on, pretreatment lice populations were estimated on 14 Jan. Each of 3 pens heavily infested with biting lice and 3 pens heavily infested with sucking lice were randomly assigned to one of the 3 treatments. For the evaluation of Poron 20 at 2 dosages and GX-118, pretreatment lice populations were estimated on 20 Jan. Six pens of cattle infested with sucking lice were randomly assigned one of 4 treatments. Two 9% amitraz dog collars, each 62.5 cm in length and 1.5 cm in width, were joined end to end through the buckle, and placed around the neck of the bovine. Several layers of filament tape were placed over the buckle. Pour-on treatments were applied according to label directions for lice control. Young's Poron was applied also at 5 ml/50 kg, the grub control dose.