Prolactin and Sexual Maturation in the Japanese Quail, Coturnix coturnix japonica

PROLACTIN has been studied extensively in birds in relation to its role in the avian breeding cycle (van Tienhoven, 1961). Assays of the pituitaries from chickens (Burrows and Byerly, 1936; Saeki and Tanabe, 1956), pheasants (Breitenbach and Meyer, 1959), California gulls (Bailey, 1952) and California quail (Jones, 1969a) revealed that prolactin is low during sexual activity and is maximal when eggs are being incubated. Prolactin has been reported to induce broodiness as well as gonadal regression in pigeons and doves (Riddle and Braucher, 1931; Riddle et al., 1933; Bates and Riddle, 1937) and in chickens (Nalbandov, 1945; Riddle et al., 1935). The results of several studies indicated that prolactin may cause gonadal regression by inhibiting follicle-stimulating hormone (FSH). In the ring dove simultaneous administration of FSH prevented prolactin-induced gonadal regression (Bates et al., 1937). In the chicken simultaneous administration of FSH but not luteinizing hormone (LH) prevented prolactin-induced gonadal regression…