Studies on the excretion of estrogen in cows following oral and percutaneous (pour-on) administration of chlormadinone acetate]

The oestrogen levels were assessed in 180 urine samples taken from 20 cows. The animals had received over 15 days 40 mg one-per-cent oily solution of chloromadinone acetate. The solution had been applied orally or by pour-on methods. The curves of oestrogen excretion were identical for both methods of application, both during and after completed administration. In other words, the effect obtainable from pour-on application is just as good as that obtainable from oral administration.