Thesis - Open Access
Master of Science (MS)
Ruminant species, which include cattle, sheep and goats, have the unique capability of digesting. cellulose and hemicellulose, the cell-wall carbohydrates that constitute 70 to 80 percent of wood fiber. By their conversion of these higher polysaccharides, which are indigestible by humans and other monogastrics, to animal products the ruminant species offer a potential means for solving the residue disposal problems of the wood industry while concomitantly extending the food supply for human nutrition. The ability of ruminants to digest the cell-wall carbohydrates depends on the microbial digestion that occurs in the reticule-rumen. This organ lies between the esophagus and the abomasum or true stomach and contains large numbers of bacterial and protozoal organisms in an anaerobic atmosphere. Many of these microorganisms possess enzyme systems which are capable of hydrolyzing the beta configuration of the glycosidic linkages which join the monomeric subunits of cellulose and hemicellulose. Through this process of enzymatic hydrolysis cellulose and hemicellulose are gradually degraded to their basic sugar units which are further metabolized to volatile fatty acids, primarily acetic and propionic. These fatty acids are absorbed through the reticule-rumen wall and serve as the main source of energy to the animal. As a potential food source wood has several advantages. It is one of the few renewable resources that is available in abundant supply and can be obtained year-round. Because its growth occurs slowly over a period of many years short term fluctuations in supply are not likely to be a problem. Its ability to grow on land area that is not well suited for human habitation or domestic crop cultivation makes it very noncompetitive for land use. Many researchers have investigated the inclusion of raw wood fiber into ruminant rations and numerous physical and chemical treatments have been conducted in attempts to improve its nutritional quality. In spite of these efforts a desirable processing technique has yet to be achieved. One of the major limitations is the nature of the raw material itself. Wood is a heterogeneous substance that varies in physical and chemical composition among genera and species. Within a single tree, composition varies cross-sectionally and longitudinally and is influenced by seasonal changes. This investigation will review previous work concerning the use of wood fiber as a ruminant feed and will evaluate the effectiveness of peroxyacetic acid treatment of wood fibers to improve their digestibility.
Library of Congress Subject Headings
Wood -- Research
Number of Pages
South Dakota State University
Ronning, Danny C., "Peroxyacetic Acid Delignification of Wood and Bark from Ponderosa Pine (Pinus ponderosa)" (1974). Electronic Theses and Dissertations. 4757.