THE MILKING STIMULUS AND MAMMARY GROWTH IN THE GOAT

Abstract

SUMMARY: The regular twice daily 'milking' of three ovariectomized virgin goats brought about mammary growth and the initiation of lactation. After several months daily milk yields of 0·8 to 2·0 1. were attained. The mammogenic and lactogenic responses to the milking stimulus were completely abolished in four virgin goats (two ovariectomized and two with intact ovaries) in which the pituitary stalk had been transected before 'milking' was started. The neurohormonal mechanisms concerned and the significance of these observations for the interpretation of studies on the hormonal induction of mammary growth and lactation are discussed.