Effects of Selenium Sources on Meat Quality and Antioxidative Capacity in Donkeys: An Integrated Study Combining Cecal Microbiota Profiling and Multi-Omics Analysis

Our study investigated the improved nutritional quality and physicochemical properties in meat, as well as growth performance and antioxidant capacity in meat donkeys, from dietary selenium (Se) yeast (SY), modulating cecal microbiota and multi-omics profiles. A total of 16 one-year-old male meat donkeys (120 ± 25 kg) were allocated to two groups: SS (0.3 mg/kg inorganic Se from sodium Se) and SY (0.3 mg/kg organic Se from SY). SY supplementation significantly increased Se and crude protein content, water-holding capacity, and cooking loss, but reduced ether extract content, shear force, and drip loss of donkey meat; SY also improved body weight, nutrient digestibility, beneficial bacteria (Agathobacter, Lactobacillus), and antioxidant enzyme activities, while reducing pro-inflammatory cytokines and malondialdehyde. Metabolomics revealed upregulation of sphingosine-1 phosphate (S1P), and transcriptomics identified enrichment of the PI3K-Akt pathway. Validation confirmed that SY elevated S1P levels and upregulated S1P receptor 2 (S1PR2) and PI3K-Akt-related genes. In conclusion, meat quality and antioxidant capacity were enhanced, and cecal microbiota in donkeys were reshaped by dietary SY. These findings indicate that dietary selenium supplementation increases Se deposition and improves the quality of donkey meat, providing a promising approach for the development of Se-enriched, value-added functional donkey meat products and processed meat items.