Breast milk Composition
Breast milk is made from nutrients in the mother's bloodstream and bodily stores. Breast milk has just the right amount of fat, sugar, water, and protein that is needed for a baby's growth and development. An average daily milk production for a lactating mother is 650 ml, though some women may produce as much as 1000 ml. Caloric value of human milk is 65Kcal/100 ml and protein being 1.15gms/100ml.
Change of breast milk composition after birth.
The composition of human milk changes rapidly during the postpartum period as secretions evolve from colostrum to mature milk. There are three stages of lactation changes that happen in the postpartum days - colostrum (0–5 days), transitional milk (6–14 days), and mature milk (15–30 days).
Colostrum: When the baby is born, a thick, yellowish milk is secreted. This milk is called colostrum and it comes out of the breast for the first couple of days . Colostrum is rich in proteins and immunoglobulins and is essential for the baby.
Transitional Milk: The secretion of transitional milk starts after colostrum and before mature milk. This secretion happens between the 4th-10th days after birth. The composition of this milk is somewhere between that of colostrum and mature milk.
Mature milk: Produced after transitional milk, mature milk continues to change over the course of the first year. The nutritional composition of breast milk gradually decreases by 10% to 30%. Due to this change in the composition of milk and the increased needs of the baby, complementary feeding needs to be introduced after your baby is 6 months old.
The composition of the breast milk changes throughout the first year of lactation.
Fore and hind milk: Breast milk also changes during each feeding session. The milk that comes out of the breast first is called foremilk and it is quite watery. Milk coming out later is called hindmilk and it is creamier and may have 50% more fat.
Encourage your baby to breastfeed: The baby should be allowed to suckle for as long as she desires for two reasons. One, to satisfy the suckling instinct of the baby and two, to express the hind milk. If the baby suckles only for a few minutes, she gets only foremilk which is thinner and just satisfies her thirst. On the other hand, longer periods of suckling feeds the baby with the hind milk which is necessary to fulfill the nutrient needs and ensure more milk production.
Source: Nutrition & Child Development by K.E. Elizabeth