The major animal feedstuffs in this compendium include green forages and dry roughages, feed grains and their processed byproducts, protein concentrates from oilseeds and animals, vitamin and mineral supplements, and other additives. How they are produced, their geographic distribution and marketing, trends in supply and demand, and the relative value of each feedstuff in animal nutrition are emphasized. Feed supplies depend on many factors, including agricultural policies, climate, soil type, and availability of processing and storage facilities. Animal inventories, proximity of supplies to animals, palatability, nutritional composition and availability, and ease of substitution between competitively priced alternative feeds determine the aggregate consumption of each ingredient.