[Triploidy as a possible cause of intersexuality in chickens (Gallus domesticus)]

A number of cases of intersexuality occurred in a fairly large number of cases in 6-8 months-old laying hens on two poultry farms in the province of Limburg. When macroscopic and microscopic studies failed to supply any evidence concerning the cause of the considerable development of the right gonad, it was decided to do a chromosome analysis. Three intersexes in which the chromosomes were studied, were found to be triploid birds showing a ZZW sex chromosome combination, which aberration may have been the cause of the intersexuality observed.