The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. ; Title from title screen of research.pdf file viewed on (April 25, 2007) ; Vita. ; Thesis (Ph.D.) University of Missouri-Columbia 2006. ; Waterfowl are renowned for their ability to exploit a wide variety of food resources. They feed on fresh and marine water invertebrates, aquatic and terrestrial plants, and agricultural grains and crops. This nutritional flexibility has allowed them to exploit virtually every water environment and establish a world-wide distribution. Their nutritional flexibility can be attributed to the diversity of anatomical, behavioral, and physiological adaptations that exist within Anatidae. Of particular importance is the ability of intestinal organs to adjust to a changing diet. The intent of this research was to investigate the role of the Canada goose (Branta candensis maxima) cecum in facilitating nutritional flexibility. True metabolizable energy assays indicated that the cecum increases the ability of the digestive system to extract energy from nutritionally poor foods (i.e. high fiber foods). Carboxymethyl cellulose assays conducted on cecal contents, confirmed the presence of cellulose-splitting bacteria within the ceca. True amino acid digestibility assays failed to detect differences in amino acid digestibility between intact and cecectomized geese. The bioassay, however, might not have been the appropriate approach to use with Canada geese. With the exception of a decrease in pancreas weight, the removal of the cecum did not lead to compensatory growth in the remaining digestive organs. Post-mortem examination, however, led to the discovery that 8 out of the 9 cecectomized geese had one or both ceca in various stages of regeneration. ; Includes bibliographical references.