Breaking Barriers in Pigeon Nutrition: How beta-Mannanase Enhances Growth and Gut Health

Objective: 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.Methods: 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: 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, BPGM) significantly correlated with growth performance and microbiota composition. Quantitative validation confirmed differential expression of selected genes.