Abstract
This study aims to investigate the effects of dietary supplementation with different concentrations of oligofructose (FOS) on growth performance, antioxidant capacity, immunity, and intestinal microbial composition in growing rabbits. One hundred female Dehua black rabbits (34 d of age) were randomly assigned to four groups (CON, FOS-1, FOS-2, and FOS-3), with twenty-five rabbits in each group. The CON group received only a basal diet, while the FOS-1/FOS-2/FOS-3 group received the diet supplemented with 0.3%/0.6%/0.9% FOS, respectively. The trial period lasted for 72 days. Our results revealed that FOS supplementation could improve the growing performance of rabbits and decrease the feed/gain ratio. FOS significantly enhanced serum antioxidant enzyme (SOD) and total antioxidant capacity (T-AOC) while reducing malondialdehyde (MDA). The levels of plasmic immunoglobulin (IgG, IgA, and IgM) and intestinal immune factors (IL-1α, IL-2, and sIgA) were significantly improved with the FOS supplement. Additionally, FOS can improve intestinal morphology and enhance the activity of intestinal enzymes, including cellulase, lipase, and protease. Furthermore, FOS supplementation influenced the composition of intestinal microflora by increasing the abundance of Lachnospiraceae_NK4A136_group (barrier-enhancing) and Monoglobus (fiber-degrading). In conclusion, the addition of FOS has a positive impact on the growth performance, antioxidant capacity, immunity, and intestinal health of growing rabbits. The optimal dietary addition for rabbits was identified as 0.6% oligofructose.