Neutral Sodium Humate Modulates Growth, Slaughter Traits, Antioxidant Status, and Gut Health in Yellow-Feathered Broilers

In this study, we explored the dose-dependent effects of neutral sodium humate (NSH) on the growth performance, slaughter traits, antioxidant capacity, and intestinal health of yellow-feathered broilers. A total of 240 one-day-old male yellow-feathered broilers were randomly allocated into three groups, with each group consisting of four replicates containing 20 birds per replicate. The control group (Blank) received a basal diet, while the NSH-L and NSH-H groups were provided with the same basal diet included with neutral sodium humate at concentrations of 0.15% and 0.3%, respectively. The results indicate that dietary inclusion of neutral sodium humate at both low (NSH-L) and high (NSH-H) doses significantly increased the body weight and leg muscle yield of yellow-feathered broilers and improved meat quality (<i>p</i> < 0.05). Furthermore, NSH inclusion effectively reduced serum total cholesterol levels and elevated total protein concentration <i>(p</i> < 0.05). In addition, NSH significantly improved duodenal and ileal morphology (e.g., increased villus height and reduced crypt depth), strengthened intestinal barrier integrity <i>(p</i> < 0.05), and enhanced antioxidant capacity (<i>p</i> < 0.05). Notably, the high-dose NSH group (NSH-H) demonstrated significantly greater enhancements in intestinal and barrier integrity compared to the low-dose group (NSH-L). Microbiome analysis revealed that, compared to the Blank group, both the NSH-L and NSH-H groups exhibited significant shifts in cecal microbiota composition, including increased abundance of <i>Bacteroidota</i> and <i>Rikenellaceae_RC9_gut_group</i> and reduced abundance of <i>Euryarchaeota</i> and <i>Methanobrevibacter</i>. Collectively, these findings demonstrate that neutral sodium humate acts as a multifunctional feed additive in yellow-feathered broilers, enhancing productivity and gut health. The study provides a theoretical foundation for the scientific application of neutral sodium humate in broiler production.