Physiology and Biochemistry of Lactation

Abstract

Cohen and Massey (1984) have pointed out that in animal reproduction ‘much more passes between the generations than simple information coded for by DNA’. In mammals, quite apart from factors such as ‘cultural inheritance’, the observation acquires tangible validity in the secretion of milk. It is sometimes overlooked that lactation is part of reproduction. Perhaps because, for over a century, increasing numbers of women have abandoned breastfeeding in favour of bottle feeding, lactation has come to be seen as an ‘optional extra’. There are very serious grounds for questioning that perception, particularly under the social and environmental conditions in which the vast majority of human babies are reared. Indeed, artificial feeding is most appropriately compared with certain other technological innovations, like artificial insemination - invaluable on occasions, but hardly to be recommended for routine practice. In virtually all mammalian species (hystricomorphs, which are very precocious at birth, are a possible exception) lactation performs a crucial role in safeguarding the reproductive investment during the early stages of exterogestate life. Short’s claim (1976) that ‘Lactation is the central control of reproduction’ has both figurative and physiological validity.