colostrum milk Ask the Chatbot a Question More Actions Share Share Share to social media Facebook X URL https://www.britannica.com/science/colostrum Feedback Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login). Feedback Type Select a type (Required) Factual Correction Spelling/Grammar Correction Link Correction Additional Information Other Your Feedback Submit Feedback Thank you for your feedback Our editors will review what you’ve submitted and determine whether to revise the article.

　　External Websites Ask the Chatbot a Question Also known as: early milk Written and fact-checked by Written and fact-checked by The Editors of Encyclopaedia Britannica Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree.... The Editors of Encyclopaedia Britannica Last Updated: Oct. 10, 2025 •Article History Table of Contents Table of Contents Ask the Chatbot colostrum, viscous, yellow-colored fluid produced by the mammary glands of humans and other mammals during the first few days after giving birth, before the onset of mature breast milk. The composition of colostrum, particularly its immune components, varies across species, mainly because of differences in placental structure. In humans colostrum production in the mammary glands starts between the 12th and 18th week of pregnancy and is the only milk released for the first few days...

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