Cellulose digestion in good and poor quality roughages using an artificial rumen.

D IGESTION experiments with cattle fed simplified rations produced results in this laboratory indicating that efficiency of roughage dry matter digestion was dependent upon the presence or absence of certain ration nutrients or feed components needed by rumen microorganisms. The nutrients or feed components which favorably influenced roughage digestion in cattle experiments were protein (N X6.~), (Burroughs et al., r949a, I949 b and I9~oa), a water extract of alfalfa hay, and the ash of good quality alfalfa hay, Burroughs et al. (I95ob). More recently a laboratory technique or artificial rumen, Burroughs et al. (i95oc) was developed for purposes of studying physiology of tureen microorganisms and making critical observations upon influential factors involved in the micro-biological digestion of roughages. Preliminary usage of this technique indicated that cellulose digestion of filter paper by rumen microorganisms could be materially influenced by the addition or withdrawal of certain substances such as alfalfa ash, a complex mineral mixture, and an autoclaved water extract of either cow manure or rumen ingesta. The purpose of this paper is to extend observations with the artificial rumen using, instead of filter paper, certain roughages commonly fed to cattle including those of both good and poor quality, respectively, and further, to present direct evidence that the efficiency with which a roughage is digested is dependent upon the presence or absence of essential nutrients in the roughage or ration which are required for maximum functioning of rumen microorganisms.