The colostrum of dairy cows refers to the milk secreted by dairy cows 7 days after calving. It is rich in vitamins, immunoglobulins and other nutrients, especially vitamins A and D, globulin and albumin, so colostrum is an essential source of nutrition for newborn calves. However, globulin and albumin in colostrum are not stable to heat, and are easy to solidify when heated, so they cannot be used as raw materials for dairy products. Of course, it can also be processed into human health food such as bovine colostrum by freeze-drying.