Ilya wrote:

>Add to that the assumption that the cattle would be fed grain and neglecting
>the sustainability of growing grain in the long term. We have depleted much
>of our topsoil. You can still continue to raise cattle on grass, but for
>how much longer are we going to be able to sustain massive grain harvests?
>Many places that used to be fertile ages ago are now deserts (not all, but
>some are because of the excessive agriculture).

Don't forget that the American plains used to have 60,000,000 bison. The
top soil was fine. They are smart enough to move to a new location before
the grass is killed off. All very sustainable.

Don.