(Merck) Mu-Se is recommended for the prevention and treatment of STD syndrome (Selenium-Tocopherol Deficiency) in weanling calves and breeding beef cattle. Each ml of Mu-Se contains the equivalent to 5 mg selenium and 50 mg (68 USP units) vitamin E. Mu-Se is administered by SQ or IM injection. Give weanling calves 1 ml per 200 lbs body weight. Give breeding beef cows 1 ml per 200 lbs body weight during the middle third of pregnancy, and 30 days before calving. Selenium and vitamin E.