The reason is as follows: 1. From the perspective of food hygiene, expired pure milk is prone to breeding a large number of pathogenic microorganisms, which will cause a high incidence of infectious diseases of the intestinal tract after entering the human body, and is prone to bloating, diarrhea and abdominal pain. 2. From the perspective of nutrition, many of the nutrients in pure milk have been decomposed. The company’s products and services are available in a wide range of sizes and sizes.