Combined supplementation effects of bacterial organic selenium and vitamin E on post-mortem meat quality, selenium bioaccumulation, serum lipid metabolism and selenoprotein expression in spent laying hens

Context Antioxidants from biological sources play a vital role in preventing oxidative cellular damage in livestock. The dietary inclusion of biogenic organic selenium produced by Stenotrophomonas maltophilia (ADS18) represents a novel antioxidant strategy in poultry nutrition. Aim This study investigated the effects of combined dietary supplementation of diverse selenium (Se) sources and vitamin E on tissue Se deposition, systemic lipid profiles, antioxidant capacity, and postmortem muscle quality attributes in spent laying hens. Method One hundred and twenty 68-week-old Lohman Brown-Classic spent hens were randomly assigned to the following four dietary treatments for 90 days: a basal control (T1), basal diet supplemented with 250 mg/kg vitamin E and 0.3 mg/kg Se as sodium selenite (T2), selenium yeast (T3), or biogenic bacterial selenium (ADS18; T4). Key results Muscle Se deposition significantly higher in hens receiving Se sources (ADS18 and Se-yeast) than in inorganic Se and control groups. Co-supplementation of ADS18 and vitamin E significantly improved systemic lipid profile, characterised by increased high-density lipoprotein (HDL) and reduced triglyceride and low-density lipoprotein (LDL) concentrations. At the molecular level, organic Se combined with vitamin E significantly upregulated SELW1 and GPX4 mRNA expression. SELW1 expression was strongly associated with Se influx, serving as a responsive biomarker of bioavailability, whereas GPX4 remained stable across treatments. However, dietary treatments did not significantly alter postmortem physicochemical meat quality parameters, including drip loss, cooking loss, Warner–Bratzler shear force, or muscle fatty acid profiles. Conclusion Combined dietary supplementation with biogenic ADS18 selenium and vitamin E effectively enhances tissue Se accumulation, optimizes systemic lipid status, and upregulates key selenoprotein gene expression in spent laying hens, without negatively affecting or altering fundamental postmortem meat quality characteristics. Implications These findings demonstrate that biogenic selenium produced by Stenotrophomonas maltophilia (ADS18), when co-supplemented with vitamin E, serves as an efficient nutritional strategy to enhance tissue selenium bioaccumulation, optimize lipid profiles, and upregulate key selenoprotein gene expression in aging spent laying hens. This provides the poultry industry with a sustainable bio-additive alternative to improve metabolic health and functional product value without compromising commercial meat quality attributes.