Effect of Prolactin Suppression on the Ovarian Activity in the Lactating Sow

摘要

The effect of prolactin suppression during lactation was studied in 6 sows nursing 5–10 piglets. In order to inhibit prolactin secretion a dopamin agonist (bromocriptine, Parlodel® “Sandoz”) was given per os from about 4 weeks after parturition until weaning 9–17 days later. Plasma prolactin and plasma progesterone were determined by radioimmunoassays. In all animals plasma prolactin was suppressed during the bromocriptine treatment. Two sows resumed ovarian activity during treatment as indicated by elevated plasma progesterone, probably as a result of the low plasma prolactin levels. The results suggest that the elevated plasma prolactin levels during lactation is one of the factors responsible for lactational an oestrus in the sow.