ONTOGENY OF THE PHOTOPERIODIC CONTROL OF PROLACTIN AND LUTEINIZING-HORMONE SECRETION IN MALE AND FEMALE BANTAMS (GALLUS-DOMESTICUS)

The development of the photoperiodic responses for prolactin and lutei nizing hormone (LH) secretion was determined in the bantam (Gallus dom esticus), which becomes somatically mature at 16-18 weeks of age. Male and female bantams were reared from hatch on short days (8 h light/da y) and photostimulated by transfer to 20 h light/day at 4, 8, 12, and 16 weeks. Photostimulation at all ages stimulated a robust increase in prolactin secretion in both sexes. Luteinizing hormone secretion was also stimulated except in 4-week-old females and 16-week-old males. It is concluded that the neural pathways involved in the photoperiodic c ontrol of LH and prolactin secretion are mature in juvenile bantams we ll before somatic maturity. (C) 1998 Academic Press.