Elionurus muticus essential oil as a dietary additive improves productive performance and promotes metabolic homeostasis in Pangasius hypophthalmus

Essential oils are increasingly used as phytogenic feed additives because they enhance growth performance, metabolism, and health in farmed fish. Elionurus muticus essential oil (EMEO) contains a high concentration of citral (73.91%), a bioactive compound with antioxidant, metabolic, and immunomodulatory properties. This study is the first to evaluate dietary EMEO supplementation in an aquaculture species and to investigate its effects on growth performance and metabolic responses in striped catfish (Pangasius hypophthalmus). Fish with an initial average weight of 18.57 g were fed five experimental diets containing 0.00 (control), 0.25, 0.50, 1.00, or 1.50 mL EMEO kg⁻¹ for 60 days (n = 150; 10 fish per 500‑L tank; stocking density 0.37 kg m⁻³). Growth parameters (weight gain, specific growth rate, feed conversion ratio) and plasma biochemical markers (cholesterol, glucose, triglycerides, total protein, albumin) were assessed. Data were analyzed using ANOVA and polynomial regression with orthogonal contrasts, with significance set at p < 0.05. Dietary EMEO supplementation improved growth performance in a dose‑dependent manner, with fish receiving 1.50 mL kg⁻¹ exhibiting greater weight gain and specific growth rate and a lower feed conversion ratio than the control group. Higher EMEO inclusion also reduced plasma glucose and total cholesterol concentrations, suggesting improved glucose and lipid metabolism, whereas triglycerides, total protein, and albumin remained unaffected. Overall, dietary EMEO supplementation at 1.50 mL kg⁻¹ shows promise as a phytogenic feed additive for practical aquafeeds by enhancing growth performance and supporting favorable metabolic regulation in striped catfish.