Castration – effects in other animals

THE PRACTICE OF CASTRATION has historically been limited to males, especially in mammals, because the gonads are generally more easily accessible than in females. It has been a common practice for millennia, probably since the first realization that the scrotal contents were associated with fertility and sexual and aggressive behavior. The aim was, of course, to control these aspects of the animals’ biology. Modern science has also made great use of castration as a tool for investigating the principles that underpin reproductive physiology and behavior in both sexes of a wide variety of species, including primates. This article concerns the anatomical, physiological, and behavioral consequences of gonadectomy in non-primate males, and in some females. Laboratory rodents have been an important source of information about the physiological mechanisms involved in responses to castration, but we are keen to limit our scope as much as possible to farm and pest animals, and particularly to mammals, because this is where the technique has been, and will be, applied to greatest benefit. In more recent times, simple surgical practices have also been developed for females, as have non-invasive pharmacological approaches for both sexes, so that now we are beginning to see an expansion of the possibilities of gonadectomy as a management tool.