The milk of the cow is most widely used by humans, but the milk of the mare, goat, ewe, buffalo, camel, ass, zebra, reindeer, llama, and yak is also used. The composition of milk varies with the species, breed, feed, and condition of the animal. Commercial dairies often supplement natural vitamin D with a concentrate.
Milk is a major source of calcium and a good source of phosphorus.
A and D have the same nutritional value as whole milk, but with fewer calories and less cholesterol . A patent was issued for the production of dried milk in Great Britain in 1855, and for concentrated milk in the United States to Gail Borden in 1856. Dried, or powdered, milk is made by passing a film of partially evaporated milk over a heated drum or by spraying it into a heated chamber in which the particles dry. Malted milk is a dried mixture made of milk and the liquid from a mash of barley malt and wheat flour.