Potato pulp as a dietary fiber source in high quality dog foods

The objective of this thesis was to evaluate potato pulp (PP) as a functional fiber source in high quality dog diets by investigating in vitro digestion and fermentation characteristics and in vivo responses to graded levels of PP in the diet. Raw and cooked PP both contained 55% total dietary fiber (TDF) with a favorable ratio (1.4:1) of insoluble:soluble fiber. Fermentation characteristics of the substrates suggested that both cooked and raw PP were moderately fermentable through 9 h. Differences in fermentability between raw and cooked PP was revealed at the 12 h time point of fermentation, where raw PP was still fermentable while cooked PP was not. The in vivo experiment revealed that graded level inclusion of PP had no adverse effects on dry matter, organic matter, crude protein, acid hydrolyzed fat, or gross energy digestibilities. Total dietary fiber digestibility increased as dietary concentration of PP increased, as did concentrations of fecal SCFA. Furthermore, fecal consistency, total fecal output, fecal protein catabolites (except spermidine), and fecal dry matter output were not affected by increased inclusion levels of PP. Overall, PP was characterized as a moderately fermentable fiber source with potential to serve as a novel fiber source in high quality dog foods