Digestion of straw by the ruminant

Publisher Website
Google Scholar
Abstract
Expts. are quoted showing the rate of digestion and digestibility of whole straw in the sheep''s rumen, and the degree to which straw remains undigested during its passage through the alimentary canal of a sheep. Much potentially digestible material is wasted. Cellulose is slowly but completely digested in the isolated state, but in straw, while digestion proceeds at first at a rate comparable with that of isolated cellulose, it slows down leaving a substantial proportion of cellulose undigested. Isolated hemicellulose is wholly digested, while in straw the pentosan-polyuronide fraction is only partially digested. Loss of lignin occurs during digestion of straw in the rumen or with rumen contents in vitro. Alkali pretreatment of straw produces a pulp which is much more digestible than the original straw. The digestibility of pentosan-polyuronide and of lignin. as well as of cellulose, is favorably affected. The reasons for wastage of nutrients in straw fed to ruminants and the means by which the wastage can be avoided are discussed.