Structure of the ruminant stomach and the movement of its contents.

Through natural development the ruminant stomach has achieved an efficient microbial digestion of plant fibre and also of almost all other plant constituents; synthesis of microbial polysaccharide and protein and of certain vitamins also occurs. The products of microbial digestion are utilized by ruminants, but they are not identical with the products of digestion in non-ruminants. I n this Symposium several of the ways in which the peculiarities of the ruminant process influence the behaviour and metabolism of these animals are discussed. As an introduction, this communication is intended to describe some of the more important anatomical features of the ruminant stomach and to consider briefly the manner in which digesta are moved through the various compartments.