What does colostrum mean?
Colostrum is the thick, yellowish fluid secreted by the mammary glands of mammals during the first day or two after giving birth, before ordinary milk comes in. Though produced only in small quantities, it is exceptionally dense with protein, antibodies, and other immune factors, which is why it is often described as a newborn's first line of defence against infection. The word appears most often in medical, veterinary, and infant-nutrition writing: paediatricians urge early breastfeeding so that babies receive colostrum promptly, and dairy farmers likewise recognise that newborn calves must ingest their mothers' colostrum to acquire passive immunity. Because of its golden colour and extraordinary protective value, it is popularly nicknamed 'liquid gold.' A formal rather than colloquial term, colostrum carries strongly positive connotations of nourishment and natural protection, and it remains an important concept in discussions of maternal health, neonatal care, and animal husbandry alike.
nounThe first thin, yellowish milk secreted by the mammary glands of a mammal shortly after giving birth, before true milk is produced. It is especially rich in antibodies and nutrients that protect the newborn against infection.
- The first milk secreted by the mammary glands of a mammal immediately after childbirth, rich in antibodies and proteins, preceding mature breast milk.
"Nurses encourage new mothers to breastfeed within the first hour so the baby receives the antibody-rich colostrum."
"The calf stood unsteadily and began to nurse its mother's nutrient-dense colostrum within minutes of birth."
"Because it contains concentrated immunoglobulins, colostrum is sometimes called a newborn's first vaccine."
The plural follows the Latin second-declension pattern; however, in practice the singular is overwhelmingly more common, even when discussing multiple samples or species.
"Researchers compared the immune properties of colostra from several mammalian species."
Known as 'liquid gold,' colostrum is packed with antibodies and has been credited with helping newborns survive before modern medicine existed.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of colostrum
The word colostrum derives directly from the Latin colostrum (also spelled colustrum), meaning the first milk of a beast after giving birth, itself perhaps related to the Greek κολόστρα (kolostra) with the same sense. It entered English in the late sixteenth or early seventeenth century, initially as a term in midwifery and veterinary practice. Its scientific use expanded in the nineteenth century as immunology revealed its antibody-rich composition, cementing its place in modern medical vocabulary.
Related word forms
How colostrum is actually used
A formal or technical term used chiefly in medical, veterinary, and nutritional contexts; in everyday speech parents may say 'first milk' instead. In farming, especially British usage, the term 'beestings' is traditional for the colostrum of cows.
Easily confused with colostrum
Colostrum is the thick, yellowish first secretion produced in the first few days after birth, whereas mature milk is the thinner, whiter milk produced later during established lactation.