Abstract
This study aimed to evaluate the individual and combined effects of chemically protected sodium butyrate (CSB) and xylo-oligosaccharide (XOS) on performance, anti-inflammatory and antioxidant capacity, intestinal morphology and microbiota of broilers. A total of 280 one-day-old Arbor Acres broilers were randomly distributed into 5 treatments: basal diet (CON), basal diet supplemented with 100 mg/kg aureomycin and 8 mg/kg enramycin (ABX), 1000 mg/kg CSB (CSB), 100 mg/kg XOS (XOS), and mixture of 1000 mg/kg CSB and 100 mg/kg XOS (MIX), respectively. On d 21, ABX, CSB, and MIX decreased feed conversion ratio compared with CON (CON: ABX: CSB: MIX = 1.29: 1.22: 1.22: 1.22), whereas body weight of CSB and MIX was increased by 6.00% and 7.93%, and average daily gain was increased by 6.62% and 8.67% at 1-21 d, respectively (P < 0.05). The main effect analysis showed that both CSB and XOS treatments increased ileal villus height and villus height to crypt depth ratio (VCR) (P < 0.05). Moreover, broilers in ABX showed lower 21.39% ileal crypt depth and higher 31.43% VCR than those in CON (P < 0.05). Dietary CSB and XOS were added individually or collectively increased total antioxidant capacity and superoxide dismutase, and anti-inflammatory cytokines interleukin-10 and transforming growth factor-β, whereas decreased malondialdehyde, and proinflammatory cytokines IL-6 and tumor necrosis factor-α content in serum (P < 0.05). Meanwhile, MIX showed the best effect of antioxidant and anti-inflammatory capacity among the 5 groups (P < 0.05). There was an interaction between CSB and XOS treatments on increasing cecal acetic acid, propionic acid, butyric acid and total short-chain fatty acid (SCFA) (P < 0.05), and the one-way ANOVA showed that propionic acid in CSB was 1.54 times that of CON, whereas butyric acid and total SCFAs in XOS were 1.22 times and 1.28 times that of CON, respectively (P < 0.05). Furthermore, dietary combination of CSB and XOS changed phyla Firmicutes and Bacteroidota, and increased genera Romboutsia and Bacteroides (P < 0.05). In conclusion, dietary CSB and XOS improved growth performance of broilers, and the combined addition of them had the best effect on anti-inflammatory and antioxidant capacity, and intestinal homeostasis of broilers in current study, indicating that it may be a potential natural alternative to antibiotics.