Milk cows are not generally used for meat. That is a different breed of cows. Milk cows almost never have male offspring - with AI we can control to ensure only female calf's are born (IIRC this is about 97% accurate so a few males are born). A few great milk producing mothers will be given sperm that is male only thus ensuring enough bulls to provide fathers and improving genetics for the next generations.

> whey itself does not necessitate killing anything.

This is assuming that people would eat calves if they weren't killed so that we can take their milk.

Mass killing is bloody and horrific.

We do it anyway.

When I sit down and think about the amount of murder required to maintain any omnivorous or carnivorous creature, it's really a mindwarp. I (at least) have been quite separated from it my whole life, until I started hunting, really.

Wolves and large carnivores especially are just brutal. They will take your children down and eat them alive in front of you. Fair exchange we drive them off and kill you quickly, is at least one way of looking at it. But there's no "pleasant" way of looking at any of it.