The only way that this would be an ethical business is if the milk were traceable into the stomach of the calf for which it was intentioned. To impregnate a sentient animal so that she will lactate and then to steal her calf once she has carried that baby 9 months to term, just as would a human mother, and then to immediately take the baby away to be turned into veal or dog food, if a male, and into a live milking machine if a female is at its very core, heartless.  My home growing up was situated between two "dairy" farms. On the days, which were often, when the babies were birthed they were taken away immediately, or very shortly thereafter, and then the crying and bellowing would begin. The mothers desperately crying to their babies and the babies answering back from distant veal crates where they were deprived even basic nutrition so that their meat would be soft and white for humans. Knowing the suffering that is behind the dairy industry I could never participate in that horror.