Why don't "cows" have a real name?
They have a collective name (cattle) and they have a scientific name (B. taurus), but they don't have a common, singular name specific to them like every other animal (that I know of) does. "Cow" is a generic term that refers to various female mammals (for example, a female moose is also a "cow").
A horse, a dog, a cat, a deer, a squirrel, a mosquito, a goat, a sheep, a chicken, a... cattle?