Influence and Degradation of Dietary Cellulose in Cecum of Rats

Abstract

Rats were fed diets containing three levels of cellulose to determine whether cellulose is an inert dietary diluent for monogastric animals. The addition of cellulose to a grain diet resulted in an increase in the quantities of volatile organic acids in the cecum. The organic acids determined were acetic, propionic and butyric acid which were probably the degradation products of cellulose. The increase of volatile organic acids in the cecum was primarily accounted for by butyric acid. The cecal contents of the rats fed diets containing higher levels of cellulose also increased. Cecectomized and intact rats were used to determine if the cecum is the primary site of cellulose degradation. The removal of cecum decreased the digestibility of cellulose; however, even cecectomized rats were able to digest substantial quantities of cellulose in a grain diet. The degradation products are postulated to be available to the rats. The three cecal volatile organic acids occurred in different proportions in the feces. This evidence suggests that the acids were absorbed or utilized differentially during passage from the cecum into the remaining large intestine.