Modern animals are domesticated and farmed, they've been brought up to be like those cows in The Restaurant at the End of the Universe which walks up to your table and politely asks which part of it would you like to eat.
To be honest, the animals which are bred in captivity would have to idea of any better living (as far as I know). It's natural for us omnivores to eat red, white, whatever colour meat but the major gripe is wastage of the food and unecessary slaughtering of meat which isn't going to be eaten, that's going to go off and then be thrown out behind the super-market.
I think that being a vegetarian is good, if it's your choice. If you were brought up a meat-eater but turned vegetarian, good on you, but what if you were born a vegetarian and had never tried meat? It's not your choice then and, (this isn't what I was building up to) like being born in the wild you should have the choice of having a future as either a herbivore/omnivore/carnivore...
That didn't finish how I meant it to, never does =S