Two questions could not be avoided in the avant-propos of this book; (i) what is the importance to man of ruminant livestock, and (ii) what results of practical relevance in the growing mountain of scientific verbiage could be found in the Proceedings of this Symposium. Herbivores are an integral and critical part of the natural ecosystem which must be preserved because of their impact on human welfare. Wh at makes ruminants especially important to man is that they can thrive on fibrous forage and are thus the only viable enterprise over much of the earth's surface where crop growing is...