Milk

Milk is a white liquid produced by the mammary glands of female mammals (including monotremes). The female ability to produce milk is one of the defining characteristics of mammals. It provides the primary source of nutrition for newborns before they are able to digest other types of food. The early lactation milk is known as colostrum, and carries the mother's antibodies to the baby. It can reduce the risk of many diseases in the baby.
The exact components of raw milk varies by species, but it contains significant amounts of saturated fat, protein and calcium. Aquatic mammals, such as seals and whales, produce milk that is very rich in fats and other solid nutrients when compared with land mammals' milk.
Humans, like other mammals, can consume mother's milk during their infancy. In many ethnic groups, people lose the ability to digest milk after childhood (that is, they become lactose intolerant), so many traditional cuisines around the world do not feature dairy products. On the other hand, those cultures that do tolerate milk have often exercised great creativity in using the milk of domesticated ruminants, especially cows, but also sheep, goats, yaks, water buffalo, horses and camels. For millennia, cow's milk has been processed into dairy products such as cream, butter, yoghurt, ice cream, and especially the more durable and easily transportable product, cheese. Industrial science has brought us casein, whey protein, lactose, condensed milk, powdered milk, and many other food-additive and industrial products.
Human milk is fed to infants through breastfeeding, either directly or by expressing the milk to be stored and consumed later. Some cultures, historically or presently, continue to use breast milk to feed their children until as old as seven years.
The term milk is also used for non-animal substitutes such as soy milk, rice milk, almond milk, and coconut milk, and even the regurgitated substance pigeons feed their young, called crop milk, which bears little resemblance to mammalian milk.