Dietary quinoa seed extract enhances growth performance, modulates lipid metabolism, stimulates immunity, and protects against Aeromonas veronii in Nile tilapia.

This study evaluated dietary quinoa seed extract (QSE) in Nile tilapia fingerlings (initial weight 6.32 ± 0.09 g). Fish were fed a basal diet (CTR) or a diet supplemented with QSE at 0.25, 0.5, or 1.0 g kg⁻¹ for 56 days. Results showed that 1.0 g kg⁻¹ QSE significantly improved final body weight (33.46 vs. 27.76 g in CTR), weight gain, feed conversion ratio, and protein efficiency ratio (P < 0.05). Furthermore, serum total protein and globulin increased, while liver enzymes (ALT, AST) decreased in QSE-fed fish. Also, digestive enzyme activities (amylase, lipase) and antioxidant capacity (catalase, GSH) were enhanced. Notably, all QSE-supplemented groups showed 100% survival following A. veronii challenge versus 50% in controls. Meanwhile, whole-body lipid content increased with QSE supplementation, correlating with upregulated pparγ and lpl and downregulated pparα expression. In conclusion, dietary QSE at 0.5-1.0 g kg⁻¹ effectively enhances growth, immunity, and disease resistance in Nile tilapia.