What about the farm animals?

I've posted before about the immorality of eating the flesh of other self-aware animals.  Yesterday blogger Arkenaten put up a post on this issue, and a couple of comments by Nan (of Nan's Notebook) raised a question about it which doesn't get discussed much:

If ALL who currently eat meat were to cease this "horrible" habit, what do you think would happen to the population of the animals currently used for food?.....Consider that ALL animals currently used for food would be allowed to graze unfettered.  They would most obviously take up "ground space.".....Also, many say the methane produced by livestock is contributing to global warming.  What if there were an even greater population of these animals?

It's a question that deserves an honest answer.  I don't think any vegetarian is so naïve as to believe that an end to meat-eating would mean that all the billions of farm animals alive at the present moment would wander off into the wild to live carefree full lives there.  There isn't enough "wild", and most farm animals are domesticated and probably couldn't survive on their own anyway.  If humans stopped eating meat, the animals that are now grown for food would cease to exist.  There's no way around that.  They're utterly dependent for survival on systems which humans would no longer have an incentive to maintain if the animals were no longer of any use to us.

But the horror of meat-eating lies in the fact that billions upon billions of animals, generation after generation of them, are constantly being produced solely to be killed, and in most cases to live stunted and miserable lives before being killed.  If humans stop eating meat, that global industrial-scale suffering ends.  If we continue, it goes on forever, generation upon generation.

In reality, of course, the end of meat-eating will not be a sudden event requiring a mass euthanasia of existing farm animals.  As awareness of the moral issue spreads, meat consumption will gradually decline, and in parallel, animal farming will gradually decrease and fewer farm animals will be bred each year as demand falls.  As meat consumption declines toward zero, the number of farm animals will do so as well.

I do not view this as a loss.  This huge population of mostly-tormented creatures would not exist in the first place if humans had not brought them into being purely in order to kill them later.  No sane human would think a life of suffering lived solely for a purpose imposed by others was worth living at all.  The moral course is to stop creating animals to live such lives.