Milk may be a nutrient-rich liquid food produced by the mammary glands of mammals. it's the first source of nutrition for young mammals, including breastfed human infants before they're ready to digest solid food. Early-lactation milk is named colostrum, which contains antibodies that strengthen the system and thus reduces the danger of the many diseases. It holds many other nutrients, including protein and lactose. Interspecies consumption of milk isn't uncommon, particularly among humans, many of whom consume the milk of other mammals.