Effects of Coated Sodium Butyrate on Growth Performance and Intestinal Morphology and Microbiota of White King Pigeon at Weaning Transition

The current study aims to assess the effects of coated sodium butyrate (CSB) on the weaning transition of White King pigeons. A total of 336 1-month-old White King pigeons were assigned randomly to four groups, including the Control group fed basal health sandand without CSB and test groups fed the basal health sand with 0.1%, 0.2%, and 0.4% CSB, respectively. The results showed that, compared with the Control group, the average daily feed intake (ADFI) was significantly increased in the 0.1% and 0.2% CSB groups (p < 0.05). The 0.1% CSB group exhibited a higher immune organ index (IOI) than the Control group (p < 0.05). The total protein (TP) and albumin (ALB) levels in the 0.1% CSB and 0.4% CSB groups significantly increased compared with the Control group (p < 0.05). In contrast, the 0.2% CSB group exhibited lower serum ALB, TP, and total cholesterol (TC) levels; TNF-α and IL-6 concentrations were reduced compared with the other groups (p < 0.05), and the 0.4% CSB group showed significantly increased serum TNF-α, IL-6, and D-lactic acid levels (p < 0.05). The ratio of villus height to crypt depth (VH/CD) of the jejunum (p < 0.05) was significantly increased in the 0.2% CSB group. In addition, the CD and VH/CD of the ileum were significantly increased in the 0.1% CSB group (p < 0.05). Firmicutes was the predominant phylum across all treatment groups, while Bacteroidota showed a more sensitive response to CSB supplementation. The 0.1% CSB group showed a significant enrichment of Oscillospiraceae and Muribaculaceae, fiber-fermenting, SCFA-producing taxa, Enterobacterales and Klebsiella, suggesting CSB-mediated alterations in luminal oxygen tension that favor the coexistence of facultative and obligate anaerobic taxa. Collectively, these data revealed that CSB supplementation efficiently improves growth performance and intestinal health of weaning pigeons by ameliorating the intestinal environment.