- Lactogenesis I means the phase when the mammary glands synthesise prenatal milk and colostrum. Colostrum contains a particularly high concentration of different immune components, like e.g. immunoglobulin IgA, lactoferrin and lysozyme.
- Lactogenesis II means the start of abundant milk production (milk comes in) two to three days after delivery.
- Lactogenesis III is the phase of maintaining lactation when the supply is primarily determined by the infant's demand.
- Lactogenesis IV is the weaning phase which starts with the introduction of complementary foods. In this phase, the concentration of different immune components (e.g. IgA and lysozyme) increase again to protect the infant against germs he or she will encounter as the baby becomes more and more active.
Ingredients of breast milk
Water acts as nutrient, solvent and means of transportation. It is also used to control body temperature. The remaining 12 % of the breast milk consist of solid components.
The main carbohydrate in breast milk is lactose (milk sugar). Lactose provides the energy required for the fast growing brain and the development of the infant's central nervous system. In addition, it supports the absorption of calcium and iron. The lactose content of human breast milk is distinctly higher than in cow's milk. The lactase enzyme breaks down the lactose into glucose (fast energy for the infant) and galactose (essential for brain development).
Apart from lactose, breast milk also contains oligosaccharides, i.e. component sugars, which promote the maturing of organs (brain in particular) and occupy the links of pathogenic germs.
The bifidus factor which is only present in breast milk fosters the growth of the bifidus bacteria which protect the infant's intestine against pathogenic bacteria, fungi and parasites.
Fat is the main source of energy (50-55 %) in breast milk. It is the component with the greatest variation, even during one feeding. The key factor for the fat content is the frequency and duration a baby suckles at the breast. Frequent breastfeeding results in a higher fat content in average as the increased oxytocin release increases lipide synthesis and lipide secretion from the alveolar cells into the milk. The fat concentration of hind milk can be 4-5 times higher than that of milk at the beginning of a feeding which makes the infant full and content.