A novel elemental nano-selenium improves growth performance and meat quality with potentially regulating muscle energy metabolism via the AMPK-mTOR signaling in finishing pigs.

BACKGROUND: Selenium (Se) is a vital trace element affecting muscle development and quality. OBJECTIVES: This study aimed to evaluate the effects of sodium selenite (SeNa), selenomethionine (SeMet), and elemental nano-selenium (SeNPs) on growth performance and meat quality and the underlying mechanisms in finishing pigs. METHODS: Finishing pigs (120 pigs/group) were fed with basal diet (CON, 0.108 mg Se/kg) or CON supplemented with 0.4 mg Se/kg SeNa, SeMet, or SeNPs. At week 6, longissimus dorsi (LD) muscle was collected for meat quality, selenium, redox status, metabolomics and transcriptomics analysis. RESULTS: and minimized drip loss than the other 3 groups. Additionally, SeMet and(or) SeNPs increased (P < 0.05) triglyceride (TG) contents and the activities of glutathione peroxidase (GPX) and thioredoxin reductase (TXNRD) in LD muscle. Metabolomic and transcriptomic profiling showed that SeNPs reduced lipid metabolic related pathways and associated with coordinated regulation of muscle and adipose tissue development. Multi-omics integration further identified the AMPK-mTOR signaling pathway as a central regulatory network targeted by SeNPs, thereby contributing to improvements in growth performance and meat quality in finishing pigs. CONCLUSIONS: Compared with SeNa or SeMet, SeNPs demonstrated a unique ability to improve growth performance, meat quality and antioxidant status in finishing pigs, associated with regulation energy metabolism by activating the AMPK-mTOR regulatory network.