Colostrum (known colloquially as beestings, bisnings or first milk) is a
form of milk produced by the mammary glands of mammals (including many humans)
during pregnancy. Most species will generate colostrum just prior to giving
birth. Colostrum contains antibodies to protect the newborn against disease. In
general, protein concentration in colostrum is substantially higher than in
milk. Fat concentration is substantially higher in colostrum than in milk in
some species, e.g. sheep and horses, but lower in colostrum than in milk in
some other species, e.g. camels and humans. In swine, fat concentration of milk
at 48 to 72 hours after parturition may be higher than in colostrum or in
late-lactation milk. Fat concentration in bovine colostrum is extremely
variable.
form of milk produced by the mammary glands of mammals (including many humans)
during pregnancy. Most species will generate colostrum just prior to giving
birth. Colostrum contains antibodies to protect the newborn against disease. In
general, protein concentration in colostrum is substantially higher than in
milk. Fat concentration is substantially higher in colostrum than in milk in
some species, e.g. sheep and horses, but lower in colostrum than in milk in
some other species, e.g. camels and humans. In swine, fat concentration of milk
at 48 to 72 hours after parturition may be higher than in colostrum or in
late-lactation milk. Fat concentration in bovine colostrum is extremely
variable.
Newborns have very immature and small digestive systems, and colostrum
delivers its nutrients in a very concentrated low-volume form. It has a mild
laxative effect, encouraging the passing of the baby’s first stool, which is
called meconium. This clears excess bilirubin, a waste-product of dead red
blood cells, which is produced in large quantities at birth due to blood volume
reduction from the infant’s body and helps prevent jaundice. Colostrum is known
to contain immune cells (as lymphocytes) and many antibodies such as IgA, IgG,
and IgM. These are some of the components of the adaptive immune system. In
preterm infants some IgA may be absorbed through the intestinal epithelium and
enter the blood stream though there is very little uptake in full term babies.
This is due to the early “closure” of the intestinal epithelium to
large molecule uptake in humans unlike the case in cattle which continue to
uptake immunoglobulin from milk shortly after birth. Other immune components of
colostrum include the major components of the innate immune system, such as
lactoferrin, lysozyme, lactoperoxidase, complement, and proline-rich
polypeptides (PRP). A number of cytokines (small messenger peptides that
control the functioning of the immune system) are found in colostrum as well,
including interleukins, tumor necrosis factor, chemokines, and others.
Colostrum also contains a number of growth factors, such as insulin-like growth
factors I (IGF-1), and II, transforming growth factors alpha, beta 1 and beta
2, fibroblast growth factors, epidermal growth factor, granulocyte-macrophage-stimulating
growth factor, platelet-derived growth factor, vascular endothelial growth
factor, and colony-stimulating factor-1.
delivers its nutrients in a very concentrated low-volume form. It has a mild
laxative effect, encouraging the passing of the baby’s first stool, which is
called meconium. This clears excess bilirubin, a waste-product of dead red
blood cells, which is produced in large quantities at birth due to blood volume
reduction from the infant’s body and helps prevent jaundice. Colostrum is known
to contain immune cells (as lymphocytes) and many antibodies such as IgA, IgG,
and IgM. These are some of the components of the adaptive immune system. In
preterm infants some IgA may be absorbed through the intestinal epithelium and
enter the blood stream though there is very little uptake in full term babies.
This is due to the early “closure” of the intestinal epithelium to
large molecule uptake in humans unlike the case in cattle which continue to
uptake immunoglobulin from milk shortly after birth. Other immune components of
colostrum include the major components of the innate immune system, such as
lactoferrin, lysozyme, lactoperoxidase, complement, and proline-rich
polypeptides (PRP). A number of cytokines (small messenger peptides that
control the functioning of the immune system) are found in colostrum as well,
including interleukins, tumor necrosis factor, chemokines, and others.
Colostrum also contains a number of growth factors, such as insulin-like growth
factors I (IGF-1), and II, transforming growth factors alpha, beta 1 and beta
2, fibroblast growth factors, epidermal growth factor, granulocyte-macrophage-stimulating
growth factor, platelet-derived growth factor, vascular endothelial growth
factor, and colony-stimulating factor-1.
Notably in humans a lack of colostrum production is linked to a mutation
in the ABCC11 gene that occurs in most people of east asian descent. This gene
is also one the determining factors in wet or dry type earwax, as the mammary
glands are a form of apocrine gland.
in the ABCC11 gene that occurs in most people of east asian descent. This gene
is also one the determining factors in wet or dry type earwax, as the mammary
glands are a form of apocrine gland.