Calves don't drink all the milk mother cow produces, they would get sick if they do. Any leftover milk is okay for human consumption. Everything you say makes no sense.
Some people obviously don't know the difference between humans and animals. Pretty sad. As a Christian I am convinced of the difference. That's why I have no problem killing an animal for consumption. An animal has no eternal spirit. Once it dies, it's dead, while a human is an eternal spirit, living temporarily in a physical body. Killing a plant is no different than killing an animal. A plant is alive too before you kill it, it just doesn't scream...
First you are a human! Religion does not define humanity, humanity defines religion.