http://www.photonette.net/

Milk

From Wikipedia, the free encyclopedia

Milk is the nutrient fluid secreted 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 more diverse foods. 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 both the mother and baby.

The exact components of raw milk varies by species, but it contains significant amounts of unsaturated 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, yogurt, 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.

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.

History

Animal milk was first used as human food at the beginning of animal domestication. Cow's milk was first used as human food in the Middle East. Goats and sheep were domesticated in the Middle East between 9000 and 8000 BC. Goats and sheep are ruminants: mammals adapted to survive on a diet of dry grass, a food source otherwise useless to humans, and one that is easily stockpiled. The animals were probably first kept for meat and hides, but dairying proved to be a more efficient way of turning uncultivated grasslands into sustenance: the food value of an animal killed for meat can be matched by perhaps one year's worth of milk from the same animal, which will keep producing milk — in convenient daily portions — for years (McGee 8–10).

Around 7000 BC, cattle were being herded in parts of Turkey. There is evidence of milk consumption in the British Isles during the Neolithic period. The use of cheese and butter spread in Europe, parts of Asia and parts of Africa. Domestic cows, which previously existed throughout much of Eurasia, were then introduced to the colonies of Europe during the Age of exploration. ^{[citation needed}]

In the Western world today, cow's milk is produced on an industrial scale. It is by far the most commonly consumed form of milk. Commercial dairy farming using automated milking equipment produces the vast majority of milk in developed countries. Types of cattle such as the Holstein have been specially bred for increased milk production. According to McGee, 90% of the dairy cows in the United States and 85% in Great Britain are Holsteins (McGee 12). Other milk cows in the United States include Ayrshire, Brown Swiss, Guernsey, Jersey, and Milking Shorthorn. The largest producers of dairy products and milk today are India followed by the USA^[1] and New Zealand.

Other milk animals

Goat's milk can be used for other applications such as cheese and other dairy products.

In Russia and Sweden, small moose dairies also exist. Donkey and horse milk have the lowest fat content, while the milk of seals contains more than 50% fat.^[2]

Whale's milk, not used for human consumption, is one of the highest-fat milks. It contains, on average, 10.9% protein, 42.3% fat, and 2.0% lactose, and supplies 443 kcal of energy per 100 grams^{[citation needed}].

Human milk is not produced or distributed industrially or commercially; however, milk banks exist that allow for the collection of donated human milk and its redistribution to infants who may benefit from human milk for various reasons (premature neonates, babies with allergies or metabolic diseases, etc.).