Sexual behavior of male dairy goats: effects of deafferentation of the genitalia.

The following study examines the effects of deafferentation of the penis, scrotum, prepuce and adjacent cutaneous surfaces on the development of mounting behavior in male dairy goats. Ten males underwent surgical deafferentations and 10 males received sham operations at 8 to 12 weeks of age. Mounting and other sexual behaviors were monitored while subjects were cohabiting with male and female penmates and when individually exposed to estrous females. Denervated males mounted penmates less frequently than sham controls and lacked vigorous thrusting behavior. When exposed to estrous females denervated goats did not exhibit the normal progression from shallow to deep thrusting with successive mounts and failed to attain intromissions and ejaculations. However, frequency of mounting was similar to that of controls when the latter were prevented from attaining intromissions. It was concluded that sensory feedback from the genitalia and surrounding cutaneous areas is not required for the initiation of leg-kicking behavior in male dairy goats but plays an important role in the development and maintenance of normal patterns of thrusting behavior. Because it was not possible to determine the rate at which reinnervation occurred, the extent to which mounting behavior depends on sensory feedback could not be determined.