Sugar beet pulp with medium water binding capacity and high fermentability improves the intestinal health and growth performance of weaned piglets

Abstract

Background This study was aimed to investigate the hydration and fermentation characteristics of fibrous materials through an in vitro study to screen out dietary fibers with varying water binding capacity (WBC) / fermentability, and evaluate their effects on the growth, diarrhea, and intestinal health of weaned piglets. Methods The hydration properties of 13 commercially available fibrous materials were first compared in terms of in vitro viscosity, WBC and water swelling capacity, followed by enzymatically hydrolysis of all the fibrous materials with pepsin and pancreatin, and in vitro fermentation of the enzymolyzed residues, during which gas and short-chain fatty acids (SCFAs) production were monitored. Subsequently, 40 weaned piglets were randomized to five experimental dietary groups (8 piglets per group): (1) the control diet (a basal diet without dietary fiber, CON), a basal diet supplemented with (2) 5% microcrystalline cellulose (MCC), (3) 5% wheat bran (WB), (4) 5% moringa oleifera leaf powder (MOLP), and (5) 5% sugar beet pulp (SBP), and their growth performance and diarrhea rate were calculated. At the end of feeding experiments, anaesthetized piglets were killed, and their intestinal and colonic digesta or plasma samples were analyzed in terms of intestinal morphology, intestinal barrier, inflammatory cytokines, SCFAs, and bacterial population. Results In vitro studies revealed a similar low WBC (2.1–2.3 g/g), but different fermentability (MCC < WB) for MCC (low WBC, low fermentability) and WB (low WBC, high fermentability) as well as a similar medium WBC (4.4–4.9 g/g), but different fermentability (MOLP < SBP) for MOLP (medium WBC, low fermentability) and SBP (medium WBC, high fermentability). In vivo studies showed that: 1) Compared with the MOLP group, the SBP group showed improved G/F ratio and reduced diarrhea rate in the first two weeks after weaning. Moreover, the SBP-fed weaned piglets were higher than the MOLP-fed weaned piglets in total SCFA concentration as well as the relative levels of Lactobacillus and Bifidobacterium, but lower in the level of Brachyspira hyodysenteriae in colonic digesta. 2) Compared with the medium WBC groups (MOLP and SBP), the low WBC (MCC and WB) groups were showed increased diarrhea and reduced apparent fecal digestibility of dry matter, gross energy, and crude protein. 3) Compared with the WB group, the MCC group showed increased crypt depth and mRNA level of tumor necrosis factor-α, but impaired jejunum barrier. Conclusions Both the WBC and fermentability of fibrous materials affected the intestinal health and growth performance of weaned piglets. The overall