Colostrum is the milk within 3-7 days after delivery. The first 3 days after delivery, colostrum begins to be secreted, the breasts are engorged and distended, and a small amount of milk will be secreted, called colostrum. Colostrum is yellowish in color, thick in texture, and contains more protein and secretory IgA, which is extremely easy to digest and can strengthen the resistance of newborns, making it an ideal natural food for newborns in the early days. Usually after 1 week, the milk will gradually increase and develop into mature milk, when the amount of protein will decrease, the color will become white, and the content of fat and lactose will gradually increase. Colostrum is very valuable and must be given to babies to strengthen their immune system and is also very easy to digest.