Cattle is colloquially referred to as cows, are disciplined ungulates, a member of the subfamily Bovina of the family Bovidae. They are raised as livestock for meat dairy products (milk), leather and as draught animals. In some countries, such as India, they are honored in religious ceremonies and revered. It is expected that there are 1.4 billion head of cattle in the world today.
Cattle were originally known by Carolus Linnaeus as three separate species. These were Bos taurus, the European cattle, including similar types from Africa and Asia, Bos indicus, the zebu,and the extinct Bos primigenius, the aurochs. The aurochs is ancestral to together zebu and European cattle. More newly these three have increasingly been grouped as one species, sometimes using the names Bos primigenius taurus, Bos primigenius indicus and Bos primigenius. Complicating the matter is the capacity of cattle to interbreed with other closely related species. Hybrid individuals and even breeds exist, not only between European cattle and zebu but also with yaks, banteng, gaur, and bison, a cross-genera fusion. Cattle cannot effectively be bred with water buffalo or African buffalo.