Toward Renewable-Based Prebiotics from Woody Biomass: Potential of Tailored Xylo-Oligosaccharides Obtained by Enzymatic Hydrolysis of Beechwood Xylan as a Prebiotic Feed Supplement for Young Broilers

SIMPLE SUMMARY: Although antibiotic resistance emerges naturally, this process has been accelerated by the worldwide overuse and misuse of antibiotics. It is essential to find effective alternatives in the broiler industry to improve poultry health while maintaining production efficiency and product safety. In this study, we aimed to evaluate a potential alternative: wood-derived component xylo-oligosaccharides. The objective of this research was to investigate the potential of xylo-oligosaccharides as a prebiotic feed supplement for broilers. Therefore, a pilot study was conducted to explore the optimal xylo-oligosaccharide profile by in vitro fermentation. Subsequently, xylo-oligosaccharides with an optimal profile were produced in large quantities, and an animal feed experiment was performed. During this experiment, the growth performance, feed conversion ratio, and intestinal parameters of the broilers were evaluated for 15 days. Results from the pilot study indicated that higher enzyme concentrations in the production process yield a product that leads to a higher butyric acid production during in vitro fermentation by caecal bacteria. Supplementation of the tailored xylo-oligosaccharides to the broiler diet resulted in higher Bifidobacterium counts, bacteria beneficial to the health of birds, from day 11 onwards. ABSTRACT: Although antibiotic resistance emerges naturally, this process has been accelerated by the worldwide overuse and misuse of antibiotics. It is essential to find effective alternatives in the broiler industry to improve poultry health while maintaining production efficiency and product safety. In this study, we aimed to evaluate a potential alternative: wood-derived xylo-oligosaccharides (XOS). The objective of this research was to investigate the potential of XOS prepared using enzymatic hydrolysis of beechwood xylan as a prebiotic feed supplement for broilers. A pilot study was conducted to explore the optimal XOS fraction profile by in vitro fermentation. Subsequently, a semi-continuous enzyme membrane reactor was used, allowing for the production of tailored XOS in large quantities. Given the strong bidirectional relationship between intestinal health, nutrition, and intestinal microbiota composition in broilers, an in vivo experiment was performed to explore the potential of XOS as a prebiotic feed supplement by investigating growth performance, feed conversion ratio, caecal short and medium chain fatty acid (SCFA and MCFA) concentration, and microbiological composition of the caecal content. Results from the pilot study indicated that higher enzyme concentrations in the hydrolysis process yield a product that leads to a higher total SCFA and MCFA- and butyric acid production during in vitro fermentation by caecal bacteria. Supplementation of the tailored XOS to the broiler diet (day 1 (d1)-d8 0.13% wt/wt XOS, d9-d15 0.32% XOS) resulted in higher Bifidobacterium counts, beneficial to the health of birds, on d11 and d15.