From what I remember meat animals aren't bred for longevity. So if you gave one each to every new veggo to eat their grass back yards they would all be heartbroken as they die an early death. Certainly meat chooks are not recommended to be kept alive for more than a couple of months as they have heart attacks and collapse from leg failure. Useful productive farm animals like milking cows and egg laying chooks are quite different from what the supermarket chains kill for us.

