Fibers fermented in the gut result in the production of short-chain fatty acids (SCFA) acetate, propionate, and butyrate. These postbiotic compounds, particularly butyrate, play an important role in colonic and host health. Fibers not degraded by the microbiota aid in stool formation and promote laxation. Many fiber ingredients are used in pet diets; however, data regarding the fermentation characteristics of alternative fiber ingredients are scarce. In this work, substrate degradation and postbiotic analysis were evaluated for apple pomace (AP), blueberry pomace (BP), cranberry pomace (CP), pea fiber (PF), and tomato pomace (TP) incubated for 1, 3, 6, and 12 h at 39 °C using canine fecal inoculum. After 12 h, substrate degradation was not different among treatments due to high variability. AP had the highest concentration of total SCFA, followed by TP, BP, PF, and CP. The molar proportion of acetate was greatest for AP and BP. CP had the highest molar proportion of propionate. PF had greater molar proportions of butyrate than did AP, BP, and CP, but had similar molar proportions as TP. Additionally, the molar concentrations of butyrate were greatest for AP and TP. Overall, fiber substrates were marginally to moderately fermentable when incubated for up to 12 h with canine fecal inoculum.

Read the full article in the Journal of Animal Science.