I have some bad news for you about the dairy industry in that they very much do kill cows. Cows producing milk requires producing constantly impregnating them. That means a lot of babies, only some of which are female and produce milk. They're seperated from their mothers and if male, killed because they're seen as waste (and would use the cow's milk because that's who the milk was meant for). Then female cows are also still usually killed after there milk production begins to decline because they're less profitable