Cows have been on earth for thousands of years, but it wasn’t until humans first tamed or domesticated some of these animals that he was able to extract and use their milk.
Cattle were probably first domesticated sometime before 9000 B.C., in India and Central Asia. But the first known domestication dates to around 6000 B.C. in Greece. We know that milk and cheese were common foods in Egypt and other ancient places by 4000 B.C.
For many centuries, cattle were raised only as work animals and as suppliers of milk. The raising of these animals as meat sources is a much more recent development.