Dairy cows are forcibly impregnated (repeatedly) because unlike what you've been taught, cows do not just produce milk. But with the milk also comes a baby cow of course, so they take the baby cow and they torture it to death (that's what veal is) or they raise it as a beef cow or as another dairy cow to continue the cycle. Now that the baby is out of the way, they steal the milk and sell it to you and repeat the process. They do this for a few years until their brutalized victim is literally too exhausted and unhealthy to produce milk anymore, at which point they murder it and sell its meat to you too (cows can live for decades, this happens after only a few years).