[pgcj_poster]

Preventing wild animals from killing each other would require by far the largest ecological intervention the world had ever seen, which would involve humans either exterminating half the species on the planet, or domesticating them and feeding them engineered vegetarian diets. In either case, it would certainly cause massive ecological damage, and I don't think we have the technology to do such a thing even if we wanted to.

This suggestion sort of like saying "Oh, you think our country should outlaw wife-beating? Well why don't we conquer the entire world and stop every country from practicing wife-beating?"

As for domesticated animals, I think we absolutely should try to find ways to feed them without killing other animals. There are companies out there trying to make vegan cat food, and although I'm not sure whether it's good enough to keep cats healthy yet, I definitely wish them luck in achieving it.