Cellulose Digestion in Good and Poor Quality Roughages Using an Artificial Rumen

Abstract

Four poor quality roughages—corn stover, wheat straw, corncobs, and mature timothy-blue grass hay—were compared in in vitro cellulose digestion studies with four good quality dehydrated forages—clover hay, rye hay, and two shipments of alfalfa hay, respectively. Supplements—including available nitrogen, a complex mineral mixture, and an autoclaved water extract of cow manure—each of which proved beneficial to the digestion of filter paper cellulose in control studies, were added singly and in combination to each of the good and poor quality roughages. The cellulose in the good quality roughages was digested efficiently without supplementation, digestion being as good as that occurring when the additions of complex minerals and autoclaved manure extract were included. Conversely, the cellulose in the poor quality roughages failed to be digested efficiently without supplementation. The additions of complex minerals and manure extract along with available nitrogen greatly increased cellulose digestion in these poor quality roughages. The results were interpreted with respect to the advantages and limitations of the artificial rumen technique in determining the nutritive requirements of rumen microorganisms and the adequacies and inadequacies of natural feeds in supplying these nutrients.