Effect of Increasing Dietary Cell Wall Content on the Digestibility of Hemicellulose and Cellulose in Swine and Rats

Abstract

Digestion trials were conducted with swine and rats to determine the digestibility of cell wall constituents—hemicellulose and cellulose, dry matter and protein when diets containing 20, 40 and 60% of orchardgrass hay were fed. The three diets were fed to swine at a restricted intake level and to rats on ad libitum and restricted intake bases. In addition, the restricted intake rats were inoculated with rumen microorganisms to test the effect of the microorganisms on the digestibility of the cell wall constituents. Hemicellulose was more digestible than cellulose in all cases in the respective trials. Increasing fiber level in the diet decreased the digestibility of dry matter and crude protein. The differences in the cell wall and cellulose digestibilities were not significant among the three treatments. Increasing the dietary fiber level decreased the digestibility of hemicellulose. Restricting the intake level in the rats did not significantly alter the digestibilities of dry matter, cell walls and hemicellulose but did significantly decrease cellulose digestibility and significantly increase protein digestibility. Inoculating the caeca of rats did not significantly increase the digestibilities of dry matter, cellulose, hemicellulose and protein. Copyright © 1970. American Society of Animal Science . Copyright 1970 by American Society of Animal Science