> Cattle can eat indigestible-to-humans cellulose in grasses and turn it into meat and milk. Grass can grow on marginal land without fertilizer or irrigation, u

> Cattle can eat indigestible-to-humans cellulose in grasses and turn it into meat and milk. Grass can grow on marginal land without fertilizer or irrigation, unlike food crops for humans. In central California I've seen cattle gaining weight on high desert scrub. When I look at the land there it looked like inedible, but to a hungry steer, it was quite passable. The wild pigs there become immensely huge, in large groups - they are a great example of how much edible food there is actually is for animals.