Cattle Lice Control, 1979

Y-Tex Tick Tags (Y-Tex Corp., Cody, WY) containing 10% chlorpyrifos were applied to heifer and bull calves on Dec 22'78. The cattle originated at several locations in south-eastern Wyoming. Animals of each sex were assigned randomly to separate pens of 6 to 9 animals each. One pen each of bulls and heifers received an ear tag in the right ear, ear tags in both ears, and no ear tags. All cattle were inspected prior to treat-ment on Dec 22'78 and then on Feb 2'79 and Mar 23'79. Lice inspection areas were 1, 15-cm hair part on the poll and 3, 15-cm hair parts on the head, brisket, neck, backline and rump-tailhead. Viable lice were determined posttreatment by microscopic examination.