Abstract

In an abattoir study in Brisbane 19 hermaphrodites were found amongst 4000 pigs (0.475%). All pigs had female secondary genitalia with a tendency towards clitoridean enlargement and excessive erectile tissue below the vulva. The gonads had developed as testes, ovotestes or ovaries and were in the position of the ovaries in normal females. Ovaries were as in normal females, apart from a possibly higher incidence of cysts. Ovarian activity was reflected by the different cyclic stages of the normal uteri at the time of slaughter. In testes and ovotestes there was no spermatogenesis, but an increased proportion of interstitial cells of Leydig and a large amount of fat. It is estimated that in a herd of pigs about 1% of apparent females may be hermaphrodites, most of which are sterile. Economic loss may be caused if these animals are selected for breeding, apart from the possibility of other congenital abnormalities in herds with a high incidence of hermaphroditism. Tainting of meat products prepared from hermaphrodite pigs may also cause economic loss. It is pointed out that the phenotypic classification of hermaphrodites is of limited value and it is suggested that a pathogenetic classification should be established for domestic animals.