Maybe in the US, where there's plenty of available space, but that's definitely not the case everywhere in Europe for instance. Also in the US, I wonder which p

Maybe in the US, where there's plenty of available space, but that's definitely not the case everywhere in Europe for instance. Also in the US, I wonder which part of that space in unsuitable for growing grain… By the way, even your Wikipedia link about backgounding mention that the animals are being given grain even in that period…