Colostrum is the milk produced by a woman’s breasts within 7 days after delivery and is characterized by its properties and nutritional value. Colostrum is usually viscous and may be yellow in color. In addition, the nutritional value of colostrum is richer than mature milk, generally containing higher protein, minerals and vitamin A, and the carbohydrate and fat content is lower than that of normal milk, and it is usually recommended that mothers should not discard colostrum after delivery, and should feed their newborns in a timely manner.1. Traits: Within 1-2 days of delivery, the composition of colostrum is close to maternal plasma, and because it contains a large amount of vitamin A original, its color is Yellow, the appearance is not like breast milk, but clean and hygienic; 2, nutritional value: colostrum contains more vitamins and inorganic salts than the later mature milk, which can promote the infant’s gastrointestinal tract peristalsis, help digestion and absorption, and facilitate the discharge of fetal stool. In addition, colostrum contains immune substances that can protect newborns from diseases, such as secretory immunoglobulin A in colostrum that will not be destroyed by gastric acid and digestive enzymes and can play the role of a mucosal protector in the intestine to protect newborns from infection by intestinal and respiratory pathogens. The composition of colostrum then changes almost daily, and the protein and inorganic content gradually decreases, transforming into mature milk after 15 days.