Dairy cows are killed for meat about 5 years into their 25 year lifespan when they stop producing as much milk. That's on top of being made pregnant (so they produce milk in the first place), having their offspring taken from them (so they don't take the milk) multiple times and male offspring being killed for veal. I don't see how it's any better than eating meat - you're still paying for animals to be killed for products that aren't essential.