(Merck) Synergized DeLice Pour-On Insecticide for Cattle, Sheep and Premises contains permethrin and piperonyl butoxide as a synergist. Faster knock-down of pests, yet low toxicity. Safe for beef, lactating dairy, sheep, and premises. Pour on at the rate of 1/2 oz. per lbs. to a maximum of 5 oz. Ready to use as a spray. Cattle rub: 1 qt/2 gal. diesel or mineral oil.