Physicochemical properties, short chain fatty acids production and in vitro fermentation of fibrous ingredients using cecal inoculum from sows

Abstract

This study evaluated and compared the physicochemical properties, in vitro fermentability, and short-chain fatty acid (SCFA) production of 13 fibrous ingredients using sow cecal inoculum. The ingredients analyzed included two commercial lignocelluloses (Arbocel® and OptiCell®), wheat bran, oat bran, beet pulp, soybean hull, citrus pulp, citrus pulp with benzoic acid (Citroflake®), dry distillers’ grains (DDG), guar gum, apple pulp, an extruded mix of tropical grasses (SmartFiber®), and a vegetable pulp mix. Bromatological composition and physicochemical properties (water-holding capacity (WHC), viscosity, and bulking) were determined alongside in vitro dry matter degradability (ivDMdeg) and fermentation parameters. Guar gum exhibited the highest hydration-related properties (WHC: 31.78 g/g; viscosity: 6.92 cP; bulking: 997.37 mL/g, P < 0.05), while DDG showed the lowest WHC and bulking (2.22 g/g and 1.76 mL/g, respectively; P < 0.05). Maximum gas production and fermentation rate were highest in guar gum and lowest in lignocelluloses and oat bran (P < 0.05). Oat bran also had the longest fermentation lag time (17.27) followed by guar gum, beet pulp and soybean hull, while citrus pulp and Citroflake® had the shortest (P < 0.05). Total SCFA production was highest in guar gum (114.1 mM), followed by beet pulp, citrus pulp, Citroflake®, apple pulp, vegetable pulp, wheat bran, and soybean hull, while lignocelluloses produced the least (P < 0.05). In conclusion, guar gum, beet pulp, citrus pulp, and soybean hull demonstrated the highest potential to influence the biochemical pathways of sows by producing significant amounts of short-chain fatty acids. Additionally, their high water-holding capacity, viscosity, and bulking properties suggest these ingredients might also enhance satiety, supporting metabolic health and welfare in sows.