Qiqi Lu, Yingying Yao, Haiying Li, Lihuan Deng, Run Wu
This study investigated the effects of substituting soybean meal with cotton protein and supplementing with benzoic acid on the intestinal health of young pigeons. A total of 240 healthy young pigeons aged 28 days were randomly divided into three groups: the basal diet group (Group A), the diet group substituting 5% soybean meal with cotton protein (Group B), and the diet group supplemented with 105 mg/kg benzoic acid in Group B (Group C). The formal experiment lasted 42 days. The results showed that in terms of intestinal enzyme activity, compared with Group A, the amylase activity and trypsin activity in Groups B and C were significantly increased ( P < 0.05), with higher amylase activity in Group B and higher trypsin activity in Group C. In terms of intestinal development, the ileal length and pH values of each intestinal segment in Group A were significantly higher than those in the treatment groups ( P < 0.05). In terms of intestinal tissue morphology, compared with Group A, the villus height of the duodenum and jejunum in Groups B and C was significantly increased ( P < 0.05), whereas the villus height of the ileum and crypt depth were significantly decreased ( P < 0.05). Compared with Groups A and C, the crypt depth of the jejunum in Group B was significantly increased ( P < 0.01). There were no significant differences in the α-diversity of the ileal microbiota among the groups, but the composition changed: compared with Group A, the abundance of the Firmicutes phylum in Group C was significantly increased ( P < 0.05), while the Lactobacillus genus was significantly decreased in Groups B and C ( P < 0.05). Metabolomics identified 66 differential metabolites, involving multiple metabolic pathways such as amino acid synthesis and ABC transporters. In summary, under the experimental conditions, substituting soybean meal with cotton protein and supplementing with benzoic acid can improve digestive enzyme activity, intestinal morphology, and the abundance of the Firmicutes phylum, thereby accelerating amino acid synthesis metabolism and promoting the intestinal health of pigeons.