Absolutely, and can you imagine what people would think if women did suckle cows? They would be regarded as insane, or perhaps considered to have some kind of perversion. God only knows what cows think of us.
Also we have been brainwashed into thinking that cow's milks is OK, but how would people feel about adding cat's milk to their tea or coffee? (I think that was mentioned in "Meet The Fokkers" with Ben Stiller.
What's the difference? It is still milk from another species.