Kolostrum

Colostrum, sometimes referred to as kolostrum in some languages, is the first form of milk produced by the mammary glands after birth. It is secreted in the immediate postpartum period and, in humans, is typically available for a short window before mature milk takes over. Colostrum differs from mature milk in composition, containing higher levels of protein and immune factors but lower lactose.

The most notable components of colostrum are antibodies, especially secretory immunoglobulin A, along with immunoglobulins such as IgG and IgM in varying amounts. It also contains lactoferrin, lysozyme, growth factors, and various nutrients. These components provide passive protection to the newborn, support the maturation of the gut lining, and influence early microbial colonization and immune development.

Across species, colostrum serves a similar protective role but its specific antibody profile varies. In dairy practice, colostrum produced after birth is sometimes collected separately because of its high antibody content and nutritional value. Bovine colostrum is widely used as a dietary supplement marketed for immune support, though evidence for noticeable health benefits in healthy people remains inconclusive. It is not approved as a medicine in many jurisdictions, and product quality can vary.

Safety and handling are important considerations. Raw colostrum can carry pathogens, so processing methods such as pasteurization are commonly used, though heat treatment can reduce some antibody activity. For infants, breastfeeding provides access to colostrum naturally, supporting early nutrition and immune defense, after which mature milk supplies ongoing nutrients and immune factors.