But what would happen if everyone became a vegan, at least pigs would become superfluous what would become of them, would they just be let loose in the wild, then a wild animal can eat them? Same goes for cattle, their only use is milk and meat and hides, so if a cow no longer gives milk, or you have too many bulls, what do you do with them? Maybe these species would disappear so as everything veganism has some good things but it also has some flaws, I don't see it as a planet saver.