The reproductive activity of autumn and spring-lambing ewes given bromocriptine during lactation.

Abstract

Abstract Reproductive activity during the first 60 days post partum was investigated in three North Country Cheviot (NCC) ewes that lambed in the autumn, and five Poll Dorset and five NCC ewes that lambed in the spring. The ewes were treated with bromocriptine (CB 154, Sandoz) from the first to the eighth week of lactation. Bromocriptine effectively reduced plasma and milk prolactin levels, but this treatment did not induce an earlier onset of ovulation or oestrus in lactating ewes in the autumn or in the spring. A clear seasonal variation in the duration of post-partum anoestrus was apparent in these animals.