Milk

Milk is usually a white liquid food, though it can appear in shades of yellow, cream, pink or brown, produced by the mammary glands of lactating mammals as the primary source of nutrition for their young before they can digest solid food. It contains many nutrients, including calcium, protein and lactose, along with saturated fat, and the enzyme lactase is needed to break down its lactose; the first milk a mammal produces, called colostrum, contains antibodies and immune-modulating components that strengthen the young animal's immune system. As an agricultural product, milk is collected from farm animals, mostly cattle, on dairies, and used by humans both as a drink and as the base ingredient for other dairy products.