Regardless of how well the animals are treated, I believe that it is wrong, even in principle, to kill animals for food when it is not necessary for our survival.

As an analogy, if O.J. Simpson had acknowledged killing his wife, but claimed that it was OK because he slaughtered her humanely, this would not be a valid defense.

Nevertheless, if farm animals were treated and slaughtered "humanely", then this would be a significant improvement to the current situation.