Analysis of teat stimulation as specific stimulus for prolactin in cattle

Experiments were performed to examine the mechanism by which the stimulation of teats of heifers and cows leads to prolactin release. It was found that the height of the prolactin peaks is strictly dependent upon the number of teats stimulated. When the teats are stimulated at short intervals, a type of sensitization to the stimulus occurs. This response may be further enhanced ifthe degree of stimulus (i.e., the number of teats stimulated) is increased. Heifers responded significantly more intensely to stimulation of teats than cows did. The stimulation of teats induces only a slight prolactin release in bulls.