a1 Department of Animal Science, Kyushu University 46-06 Hakozaki, Fukuoka 812, Japan
Accessory reproductive fluids and organs of male domestic fowl, turkeys, ducks, quail, guinea fowl and pigeons were examined. Male domestic fowl, turkeys and ducks produced different quantities of accessory reproductive fluids – lymph-like fluid and/or foam – during natural copulation. Quail released a unique foam, which is produced constantly in the cloacal region regardless of the ejection of semen and the time of day. The natural ejaculate of this species is always associated with the release of foam. In contrast, guinea fowl and pigeons released neither lymph-like fluid nor foam at ejaculation when semen was collected using the lumbar massage method. The tissues and organs which are involved in the production of these accessory reproductive fluids are the paracloacal vascular body (PVB), lymphatic folds (LF), dorsal proctodeal glands (DPG), ejaculatory groove region (EGR) and tissues in the vicinity of the papilla of the ductus deferens (TVP). Guinea fowl possessed the PVB, DPG and TVP even though they produce no accessory reproductive fluids. The only exception was the pigeon which has neither the tissues nor the organs listed above. The accessory reproductive fluids have a favourable effect on the function of freshly ejaculated spermatozoa in domestic birds.