Mastectomy and mammary glands in reproductive control in the goat

Abstract

Little attention has been paid to the role of the mammary glands in reproduction apart from the suppression of reproductive activity during lactation in some species. A hint of greater involvement, however, stems from two observations in the goat. First, Linzell¹ reported that while developing his technique of transplanting mammary glands to other sites in the body in order to gain access to the mammary artery, the incidence of reproductive disturbances (infertility, abortion and apparently inexplicable maternal death at parturition) seemed greater in goats which had lost mammary tissue post-operatively, or which retained only one mammary gland, than in others in the herd and second, the mammary glands may significantly influence the concentration of a hormone in the general circulation^2–5. Moreover, in some marsupials there is evidence that the mammary glands are involved in the control of reproduction, for example, denervation of the mammary glands during lactation initiates development of the diapausing embryo⁶. In view of the importance of reproductive integration in the artificial control of fertility, we have followed up these clues by investigating the effects of mastectomy in the goat, a species with a seasonal, rather than a lactational, anoestrum. We report here that the oestrous cycle was markedly disturbed by mastectomy and that fertility, and possibly also the length of gestation, seemed to be affected.