Aw, skib, you are modest, but I think you are very intelligent. You may leave if you wish but we'd love to have you stay. I don't post long posts nowadays, I just try to say what I wish concisely, though I may fail to always communicate clearly.
Anyway you raised a valid point. My own suggestion in response would be something like, reducing the population in a controlled way (this would definitely be feasible as an evolution to vegetarianism could not be but gradual), gradually.
If we control the numbers of animals - "we," such a big call for quotations - then it is not difficult for us also to diminish those numbers, by not breeding them. It does not seem to be a potent argument to me to say "we bred these animals, so we must eat them." In fact I see no limitation on our ability to decrease their numbers. If we did not breed them at all they would cease to exist in a generation. I am not saying we should act so to make them cease to exist, but merely point this out to show our ability to act with a free hand there.
And also as mono says, we can live in harmony with the animals. Cows are sacred in India and much revered, as are elephants. As Becca said, why are some animals such as dogs and cats considered pets, loved, part of the family, while others are not? In fact pigs are smarter than dogs. Dogs are pack animals and so they naturally fit in perfectly with our families, but pigs are certainly able to learn a great deal as well.

