Avian reproductive anatomy, physiology and endocrinology. |
| |
| Authors: | Christal G Pollock Susan E Orosz |
| |
| Institution: | Department of Clinical Sciences, College of Veterinary Medicine, Kansas State University, 1800 Denison Avenue, Manhattan, KS 66506-5606, USA. cpollock@vet.ksu.edu |
| |
| Abstract: | Although many environmental cues influence reproductive activity, the seasonal breeder responds most strongly to long day length. THE MALE BIRD: Testicular interstitial cells secrete testosterone, which influences reproductive behavior such as territorial aggression and song. Other changes observed in seasonal breeders include testicular hypertrophy and enlargement of the ductus deferens and seminal glomus. THE FEMALE BIRD: Early changes associated with rising estrogen levels in the hen include osteomyelosclerosis and hypercalcemia. Ovulation is then induced by LH, which is followed by eggshell calcification, which is under the control of progesterone. Sources of calcium for shell production include intestinal absorption from the diet, renal control of calcium levels, and mobilization of bone calcium stores. During oviposition, PGF2 alpha and vasotocin stimulate powerful uterine contractions 32] in the presence of calcium. Incubation is associated with falling LH levels and rising prolactin levels. If the hen actually enters reproductive quiescence at this time, then molt will follow. Molt is associated with the total regression of the reproductive tract. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
