Effects of Plant Polysaccharides on Meat Quality of Squabs Based on Ileal Metabolomics

Plant polysaccharides, such as Astragalus polysaccharide (APS) and Glycyrrhiza polysaccharide (GPS), hold potential as feed additives, yet their individual and synergistic effects on squab meat quality remain unclear. In this study, 192 healthy, 15-day-old, early-weaned Silver King squabs were assigned to one of four dietary treatments for 28 days: a control group (CK), an APS group, a GPS group, and a combined APS + GPS group (AG). Slaughter traits, organ indices, liver antioxidant capacity, and meat quality were evaluated across the four groups. Results indicated that supplementation with APS, GPS, and AG enhanced several slaughter traits compared to CK, including live weight, carcass weight, full-eviscerated weight, half-eviscerated weight, and leg muscle weight. GPS and AG supplementation improved color parameters in both breast and leg muscles, with AG showing the most favorable tenderness-related outcomes. Additionally, AG supplementation enhanced liver antioxidant capacity, as evidenced by increased total antioxidant capacity and superoxide dismutase activity. Given AG's superior overall performance, the ileal metabolomics analysis focused on comparing CK and AG. Metabolomics data revealed clear group separation and significant changes in amino acid-related pathways. In summary, while APS and GPS individually improved certain traits, their combined supplementation yielded the most favorable results, likely through enhanced antioxidant capacity and altered ileal amino acid metabolism.