No other species drinks the milk from another species regularly. It's definitely not true to say that any predator that preys on mammals will drink the milk of their prey. It happens in rare circumstances with certain species. The way we artificially inseminate dairy cows, steal their babies and kill them, and steal the milk made for them, in industrialised farming systems, is far removed from nature.
Normal is one thing, which I would dispute. Acceptable is based on your opinion, which I think is highly flawed and unethical. Causing suffering and harm to animals by separating them from their mothers and killing them is cruel. Therefore I wouldn't say it's morally acceptable at all given that the whole industry is unnecessary, and harmful in a number of ways.
A carnivore eating an animal and including their mammary glands in the flesh they're eating is very distinct from deliberately drinking their milk, either suckling on their teats or milking them. It's a very rare practice ("milking" another animal never happens in nature, as we do), but humans have made it a norm for our species. Human adults were lactose intolerant by default before the lactase persisten gene developed as an adaptation to tolerate drinking cow's milk made for calves. My point being it wasn't previously normal for humans either. It's an avoidable practice, so arguing that the processes involved in it are necessary is simply untrue and logically false.
It's really not. What we do, exploiting an animal directly for their milk, is not normal in the animal kingdom. You're trying to argue that it is because mammaries are part of the meat that some animals consume. That's a false equivalency.
You’re trying to argue that it is because mammaries are part of the meat that some animals consume. That’s a false equivalency.
i think it's absolutely no different ethically, but what differences exist make our practices more humane: we don't murder a cow every time we drink milk.
That's pretty messed up. Of course it's cruel. Only a person who lacks empathy for animals would say that causing suffering to an animal unnecessarily isn't cruel.
there is some question about whether it's justified, sure, but it's not inherently cruel. the suffering isn't the point of the practice, it's incidental.