"To say that since we have decided to kill animals, the only criterion is effectiveness (whatever effectiveness means), and so are engaged in moral evil and can therefore turn a blind eye to what that entails is what a lot of people do, but it is shaky."

Peter, I think you've imported some of that emotional content I noted into the meaning of my remarks. "Raising animals for food" includes breeding, birthing, feeding, and, in the end, killing. You are free to consider that process a 'moral evil' if you choose, as I am free to disagree.

Given the reluctance of the human species to regulate its own population growth rate, organized production of foods is a necessity.
"Hunting and gathering" has become mythologized in many respects, but is simply not a practical method to feed the world population. When the effect of modern techonolgies is plugged into the equation, hunting and gathering becomes environmental devastation. How do you propose the collective "we" feed ourselves?