I'm glad you're being intelligent about this as usual, Bay 12. I was hoping people wouldn't say that we should stop eating animals for illogical ideological reasons. However, the same counterargument still holds ground; if we don't need meat we wont bother with the animals that give it to us. They'll be mass cullings, and i suspect it would take many generations for the amount of animals that have lived human free in the wild outstrip the ones killed then or because of overgrazing and suchlike from a lack of natural predators.
... I can only half parse that for some reason, but nah, there's not really enough
left of the wild, by and large, to support the current farmed population, so far as I'm aware. But preservation issues are a sorta' separate issue, for all that the consequences of actually stopping animal farming would be pretty significant regarding the animals themselves (I'd give strong odds a good chunk of them would be extinct within a few generations, t'be honest, if only because a goodly number of the non-domestic relative species are already endangered, from what I understand.).
I'm pretty sure cows and chickens would go extinct pretty quick if we left them to their own devices.
Naaah, chickens would probably be fine, I think. There's still decent wild populations of those, iirc. They're vicious little bastards, and their dietary habits (i.e. goddamn everything) means they've got a pretty decent range. Cows... less so. That's more of a range issue, and it's pretty much a given we're not going to yield much land to 'em if we're not eating them.