Here is one of the challenges for civilized humankind: to learn (again!) from the animals and the plants, rather than use them like dead matter or animate machines for our needs and ends. They can be sources of inspiration for adaptive techniques and technologies; they are keepers of a kind of quiet wisdom we are only beginning to appreciate.
The cow knows how to live on cellulose, the deer and the horse, too. They know how to live outside, in all weathers, needing only the barest essentials. They will still be here long after our fossil-fuel-driven civilization grinds slowly to a halt.