True hermaphrodites in a flock of Cochin bantams.

Three birds from a flock of 125 Cochin bantam chickens were true hermaphrodites, having both ovarian and testicular tissues. These birds were recognizable by their intermediate comb size, intermediate plumage, and spur development. At necropsy, the left gonad of all three birds was an ovotestis and the right gonad was a testis. Microscopically, both ovarian follicles and seminiferous tubules were present within the ovotestes. Chromosomal analysis of lymphocytes from the whole blood of the third bird revealed triploid ZZW sex chromosomes. This high incidence (2.4%) of hermaphrodism suggests that there may be a hereditary predisposition for genetic intersex.