In fact, human milk can be divided into colostrum, transitional milk, mature milk and late milk. The biological components and characteristics of human milk are different in different stages.
1. Colostrum: the milk within 5-7 days after delivery is called “colostrum”. Colostrum is less, thick and yellowish. Compared with mature milk, it has higher proportion, more protein content, less carbohydrate and fat.
The proportion of whey protein and casein in colostrum is about 80:20. The protein is mainly secreted immunoglobulin IgA and lactoferrin, which is easy to absorb. Colostrum is rich in antibodies and immune substances, which can increase the baby’s resistance. There is no scientific basis for the old idea to discard colostrum.
2. Transition milk: transition milk refers to the transformation from colostrum to mature milk within 7-14 days after delivery. During this period, the milk yield increased gradually, the content of immune substance and protein decreased, while the content of fat and lactose increased gradually, so the heat content increased.
3. Mature milk: the human milk from 2 weeks to 7-8 months after delivery is called mature milk. At this time, the proportion of whey protein and casein decreased to 55:45. The milk secretion will increase obviously. Because “mature milk” looks a little thin, some mothers will think that their milk is too thin and has no nutrition. In fact, the milk is rich in nutrition and can meet the needs of baby’s growth and development.
4. Late milk: late milk refers to breast milk 7-8 months after delivery. Compared with mature milk, the proportion of protein, fat and carbohydrate has little change, but the nutritional components such as vitamins and minerals have gradually decreased.