If you're looking for practical specifics about adding animals to your sustainable living plan, the library can help.
Try general works such as The Joy of Keeping Farm Animals : the Ultimate Guide to Raising Your Own Food by Laura Childs or specific titles (goats, poultry, sheep, etc.) from the folks at Storey Books. Also try the broader work Homesteading : a Backyard Guide to: Growing Your Own Food, Canning, Keeping Chickens, Generating Your Own Energy, Crafting, Herbal Medicine, and More edited by Abigail R. Gehring. This one offers a variety of ideas to the eco-minded, twenty-first-century homeowner.