Lactation

By the process of lactation, the mammary glands of the female begin producing milk towards the end of pregnancy. Prolactin is the hormone responsible for this milk production, and lactation allows the mother to feed her newborn baby. The fluid secreted by the mammary glands immediately after childbirth is called colostrum — a sticky, yellow fluid containing proteins, lactose and the mother's antibodies (for example, IgA), though it is low in fat. The antibodies present in colostrum help the newborn build resistance to infection at a stage when its own immune system is not yet fully developed.