Cow’s milk is a white liquid with nutrient-rich properties obtained from the mammary glands of a cow that has given birth. Cows can be milked manually or with machines. Milk is a primary source of nutrients for mammal infants, including humans. Early milk contains colostrum, which is essential for the transfer of antibodies from the mother to her young in order to prevent illness. People consume cow’s milk to obtain the nutrients necessary for growth and development. Cow’s milk is often pasteurized and packaged for sale and, when properly processed, can have a shelf life of up to two months. Powdered milk lasts even longer. Although cow’s milk provides many nutritional supplements, some people are allergic to cow’s milk and its products and, therefore, need to use a substitute.