The cow is a prominent modern member of the subfamily Bovinae, and is the most widespread species of the genus Bos. More about cattle on Wikipedia . The cow is used for meat, milk, leather, as a working animal and for entertainment/sport (rodeos, bullfighting and other fiesta's)

Cow/Cattle Fact sheet World Animal Foundation 
The secret Lives of Cows Animals Australia
The Private Life of Cows BBC
Cow researchers find meanings behind moos BBC News
Cows are more intelligent than you probably thought Huffington Post