You're right, but I think about it the other direction. We currently _do_ eat the calves that _are_ killed so we can take their milk.
We _could_ (probably) figure out a way to not require killing them, I just don't know what that would be.
We _could_ (probably) figure out a way to not require killing them, I just don't know what that would be.
If god appeared and said that the Hindus were right all along and cows are sacred and milk is their gift to us - we'd do it just fine.