ABSTRACT
Domestication of ruminant animals and their use to produce milk, meat, wool, and hides represents one of the cornerstone achievements in the history of agriculture. The essential feature of the ruminant animal that has fostered its utility as a dairy animal is the presence of a large pregastric chamber where microbial digestion of feed (particularly fibrous feeds not directly digestible by humans) provides various fermentation products that serve as precursors for efficient and voluminous synthesis of milk. Without this symbiosis between animal and microbe, the dairy industry would not have developed, and indeed human culture would be vastly different in its food-gathering methods.
