Induction of Parturition in Cattle with Cloprostenol

Abstract

Four cows were induced to calve prematurely by a continuous intravenous infusion of cloprostenol, a prostaglandin analogue, and 64 cows and heifers were induced by a single intramuscular injection. No advantage was evident from the continuous administration of cloprostenol compared with the single injection. Sixty-one of the 64 injected animals (95%) calved at a mean time of 47 h after treatment, 37% needing assistance with delivery of the foetus. 91% of the calves were born alive and 62% of the cows retained their placentae. The time from treatment to calving and the incidence of dystocia, placental retention and metritis were all greater the earlier in gestation that cloprostenol was administered. No drop in milk yield resulted from induction and subsequent fertility was acceptable. Cloprostenol caused a marked fall in peripheral plasma progesterone concentration and parturition occurred 24 h after basal levels had been reached.