Speaking of bovines: they, unlike humans, are able to digest cellulose (although technically they rely on symbiotic bacteria in their intestinal tract to produce the needed enzymes.)
So what? Well, west of the about the 98 degrees West Longitude in the U.S. there isn't quite enough precipitation to support growing much food that is directly digestible by humans. But the area has native plant material well adapted to that environment that, while inedible to humans, is suitable for grazing cattle. So cattle ranching in those areas actually makes land productive that would otherwise be of marginal utility. The cattle could be thought of as roaming self-powered factories that convert inedible "woody" plant material into juicy and tasty heart-attack inducing steaks. :wink2:
(All the above is from material I've read elsewhere and could contain factual errors. But it sounds plausible enough to me to be worth posting.)
