MILK ANIMALS OF THE WORLD
Being used to cow milk here in the western world, there are more - exotic and common - animals from which we can obtain this lovely fluid. The nice thing about dairy animals is that they can produce milk from foods that we humans do not really appreciate, that is grass or hay, or other plants. This is probably also the reason that we have dairy animals in the first place, otherwise, how would they survive the course of nature?
Cow - Bos taurus
Bos taurus is the latin name for the common cow, and it is believed that it originates from a somehow bigger cow that measured about 6 ft (180 cm) at the shoulder. Thank God, it became smaller! This cow ancestor was domesticated about 10,000 years ago, when the slow agricultural revolution spread around the world and people turned from nomads to settlers. The cow as it is today is a product of slow and progressive breeding, and the smaller size is a result of the worsened food that the breeders served the cow during harsh winters.
Buffalo - Bubalus bubalis
Water buffalo milk may not be that common in our civilization, and the best known dairy product coming from the buffalo is probably mozzarella (mozzarella di bufala). Now I mean the real mozzarella, and not the poor less flavored imitation. Water buffalo loves water simply for the sake of cooling its body temperature, as it is very heat-sensitive. Buffalo milk has more flavor than cow milk, with a slightly higher fat and protein content.
Yak - Bos grunniens
Yak is a long-haired animal with the typical big pointing horns, and it can be found living in the wilderness of Asian plateaus and mountains. Of course, some yaks in our world are domesticated, and yak milk is also richer in fat and protein as compared with cow milk.
Goat - Capra hircus
Goats are well-known mountain climbers, and they are perfectly allright with scarce food that doesn't even have to be moist. Due to its small size, goats were domesticated early,
and turned out to be producing a nicely flavored milk.
Sheep - Ovis aries
Sheep was also domesticated early, not only for the milk but also for the wool and meat. Sheep milk is very rich in fat and protein, and is used for production of special kinds of cheeses (Roquefort, pecorino, feta).
Camel - Camelus dromedarius
Camels are very well adapted to warm climate and are the only mammals that can raise their heat tolerance before they start to "sweat". They are kept as "house" animals mainly by nomadic tribes, so camel milk may not be readily available to a common man. However, camel milk is rich in fat and protein, and is said to have many curative properties, so when the opportunity arises...
(images from http://wikipedia.org)