LACTATION IN THE GOAT AFTER SECTION OF THE PITUITARY STALK

Abstract

SUMMARY The pituitary stalk was sectioned in a series of goats, some of which were pregnant and others lactating. At operation a plate was inserted to form a barrier between the cut ends of the stalk. Some of the goats operated on during pregnancy came into lactation a few days after aborting (9–17 days after operation). In the goats operated on during lactation there was an immediate marked fall in the milk yield, but it was found that lactation might continue at a reduced level for some considerable time. Restoration of a substantial degree of lactation was obtained by giving a combination of somatotrophin, triiodo-l-thyronine, insulin and corticosteroids, without prolactin. Since lactation can only be restored in the hypophysectomized goat by giving prolactin in addition to these four hormones it seems probable that in the stalk-sectioned goat some prolactin is secreted by the relatively few surviving cells of the anterior lobe, although they are deprived of direct hypothalamic stimuli.