colostrum

In mammals, the yellowish milky fluid secreted by the mammary glands immediately before and after giving birth, which is followed by the secretion of the true milk.

Colostrum (also known as beestings or first milk) is a form of milk produced by the mammary glands in late pregnancy and the few days after giving birth.

Human and bovine colostrum is thick and yellowish.

Colostrum is high in carbohydrates, protein and antibodies, and low in fat, which human newborns may find difficult to digest. Newborns have very small digestive systems, and colostrum delivers its nutrients in a very concentrated low-volume form.

Colostrum contains large numbers of antibodies called "secretory immunoglobulin" (IgA) that help protect the mucous membranes in the throat, lungs, and intestines of the infant.

Premature babies tend to fare better on human colostrum than manufactured baby milks. Human milk contains special components, called growth modulators, that help the premature baby's digestive system adjust to oral feedings (Davies 1989). Lucas 1984) indicate that premature babies fed formula tend to vomit more and continue tube feeding longer than those fed human colostrum and breast milk.

Bovine colostrum is sometimes used by humans as a dietary supplement. Purified bovine colostrum extract is also sometimes used in protein supplements used by athletes and bodybuilders.