Breaking Barriers in Pigeon Nutrition: How beta-Mannanase Enhances Growth and Gut Health
Pigeons differ from other poultry in that they rely entirely on parental nutrition during early growth, underscoring the critical role of parent pigeon nutritional status in squab development. Although plant-based feeds (peas, corn and sorghum et.al) are widely used for parent pigeons, they contain anti-nutritional components like beta-mannan in plant cell walls. These components interfere with nutrient release and absorption, necessitating the development of optimized feed formulations. This study randomly assigned 600 one-day-old squabs to four groups: control group (C) and three experimental groups supplemented with 0.025% (L), 0.05% (M), and 0.075% (H) beta-mannanase. The optimal supplementation level was determined based on squab production performance, with effects on intestinal morphology evaluated. Results showed that the M group exhibited the highest weekly body weight, average daily gain, and nutrient digestibility (P < 0.05). Production performance analyses revealed significant improvements in chest width, keel length, pelvic width, slaughter rate, and evisceration rate in the M group (P < 0.05). Intestinal morphology assessments indicated that 0.05% beta-mannanase increased villus height and the villus/crypt while reducing crypt depth (P < 0.05). Gut microbiota analysis via 16sRNA sequencing showed enhanced alpha- and beta-diversity in the M group, with increased beneficial bacteria (Limosilactobacillus, Enterococcus_E, Streptococcus) and reduced potentially harmful species. Functional predictions highlighted alterations in glycolysis and carbohydrate metabolism pathways. Transcriptomic analysis of the ileum identified 1912 differentially expressed genes, with key glycolysis/gluconeogenesis-related genes (TPI1, PGAM1, PGE1) significantly correlated with growth performance and microbiota composition. Quantitative validation confirmed differential expression of selected genes. In conclusion, dietary supplementation with 0.05% beta-mannanase enhances squab growth by improving nutrient digestibility, modulating gut microbiota, and regulating metabolic gene expression. These findings provide theoretical support for optimizing pigeon farming efficiency and sustainable specialty breeding strategies.