title: Concentrations of plasma luteinising hormone, prolactin, progesterone and androgens during the ovulatory cycle of the turkey.
abstract: 1. Changes in the concentrations of plasma luteinising hormone (LH), prolactin, androgen and progesterone were measured during the ovulatory cycle of the turkey. 2. Single pre-ovulatory peaks of plasma LH, androgen an progesterone were observed which took 8, 8 and 12 h respectively, to increase and return to base-line values. The concentration of plasma prolactin tended to be elevated between 6 h before and 6 h after the LH peak with the maximum values occurring after the peak. 3. The changes in the concentrations of plasma LH and progesterone were 3- and 7-fold respectively while 2-fold changes were observed in the concentrations of plasma androgen and prolactin. 4. The pre-ovulatory concentration of plasma progesterone and prolactin began to decrease 4 and 6 h respectively, after the pre-ovulatory peak of LH. 5. Ovulation and oviposition occurred 6 to 8 h and 36.10 +/- 0.57 h (SEM) (n = 11) respectively after the pre-ovulatory peak of LH. 6. In birds kept on 14 h light/d, pre-ovulatory peaks of LH were initiated only during a 10 to 11-h period starting within 2 h after the onset of darkness. 7. A comparison between these data and those from the fowl suggest that the egg is retained in the turkey's oviduct for about 3 to 4 h longer than in the fowl.
mesh_terms: D000728:Androgens / Q000097:blood; D000818:Animals; D005260:Female; D007986:Luteinizing Hormone / Q000097:blood; D010060:Ovulation; D011374:Progesterone / Q000097:blood; D011388:Prolactin / Q000097:blood; D014422:Turkeys / Q000097:blood* / Q000502:physiology
chemical_list: D000728:Androgens; D011374:Progesterone; D011388:Prolactin; D007986:Luteinizing Hormone