The effect of ovariectomy on broodiness and plasma prolactin levels in turkey hens during a photo-induced reproductive cycle

The effects of ovariectomy on broody behavior and plasma prolactin levels were examined in turkey hens that had previous histories of broodiness. Ovariectomy eliminated all nesting behavior and blocked the photostimulated increase in plasma prolactin observed in sham-operated hens. Sham-operated hens demonstrated egg-laying patterns and nesting behavior typical of broody hens. A large increase in plasma prolactin preceded broody behavior which continued as long as the elevated amounts of plasma prolactin persisted. It was concluded that the ovary is essential in expressing broody nesting behavior, the large increase in plasma prolactin associated with this behavior, and the prolactin increase in hens that did not demonstrate nesting behavior.