Well, I think it is both. I find it quite cruel to kill animals. Even more cruel to breed animals just to be able to kill them later. It's quite a twisted moral towards a sentient being. No animal wants to be killed.
If they could be raised in humane, unlike mass production conditions, then one could argue convincingly that it's better than not doing it all from a purely compassionate viewpoint.
It's still tremendously wasteful of land and resources, but that's a separate concern to address.