For the last 36 hours, since seeing “Eating Animals,” I have had trouble consuming meat. O.K., I had some lox, but probably only because the movie doesn’t deal with ocean fish.

Christopher Quinn’s documentary makes a persuasive, far-ranging case against factory farming, which it skewers from philosophical, epidemiological and even economic perspectives. Factory farms may make it possible to feed more people, but their environmental effects may make their efficiency a Pyrrhic victory. The movie isn’t even advocating vegetarianism. But it seems impossible to come away from it without wanting to know more about where your meat comes from.