Morphology of the Turkey Vagina and Uterus With and Without an Egg Mass

Authors: Bakst, Murray; Akuffo, Valorie

Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/2/2008
Publication Date: 7/13/2009
Citation: Bakst, M.R., Akuffo, V.G. 2009. Morphology of the Turkey Vagina and Uterus With and Without an Egg Mass. Poultry Science. 88:631-635.

Interpretive Summary: The turkey vagina is embedded in connective tissue and has a minor role in egg formation. Yet, this segment is responsible for the transport of a small number of select sperm that eventually will fertilize ova. We know very little about this important segment of the turkey’s oviduct. In this study we described the complex shape of the vagina and related its anatomy to its functions. In doing so we have shown that the male and female sex organs of birds do not necessarily coevolve to have either a positive or negative impact on reproduction. To the contrary, we suggested that the driving evolutionary force behind the condensed coiled and/or folded appearance of the vagina was due to the need to accommodate its long length in a limited abdominal space. This work is useful to scientists studying animal breeding behavior and also provides descriptions of the fate of sperm in the oviduct with or without an egg useful to poultry and avian biologists.

Technical Abstract: In this study we examined the gross anatomy of the uterus and vagina in turkeys in egg production. With no uterine egg mass, removal of the tunica serosa that enclosed the uterus revealed deep periodic in-folding of the muscularis transversely circumscribing the sac-like segment. When the connective tissue compressing the vagina was completely teased free, the exposed tubular segment was either oriented into counter-clockwise spiral curves or angular, random bends.. The uterovaginal junction either was flush with the uterine mucosa or projected slightly into the uterine lumen. With a uterine egg mass, the morphology of the vagina was not altered except that the uterovaginal junction appeared dilated at it juncture with the uterus. Whether an egg mass was present or not, uterovaginal junction folds that projected into the uterus possessed sperm storage tubules. We suggest that for the turkey and possibly other species possessing a non-intromittent phallus, vaginal pleomorphism was driven primarily by the need to accommodate the length of the vagina in limited body space and to a lesser extent on sexual selection