Nutraceutical potential of prekese (Tetrapleura tetraptera) fruit extract: synergizing growth performance, oxidative stability, and economic viability in Nile tilapia (Oreochromis niloticus)

Abstract

This study evaluated the effects of dietary Prekese (Tetrapleura tetraptera) fruit extract (PFE) on the growth, haemato-biochemical profile, antioxidant status, and economic efficiency of Nile tilapia (Oreochromis niloticus) fingerlings. Five isonitrogenous (35% crude protein) and isolipidic diets were formulated with graded PFE levels: 0.0 (control), 5.0, 10.0, 15.0, and 20.0 g/kg. Fish (5.20 ± 0.05 g) were fed twice daily to satiety for 60 days. Gas chromatography- mass spectral analysis of PFE identified 29 compounds, primarily linoleic (20.46%), myristic (14.53%), and oleic (12.49%) acids. Dietary PFE significantly enhanced growth in a dose-dependent manner (P< 0.05). The 20.0 g/kg inclusion yielded a higher final body weight (35.04 g) and weight gain (571.97%), a 121.9% increase over the control. Polynomial contrasts identified 20.0 g/kg as the upper limit for growth and feed efficiency in this study. Haematologically, PFE increased red and white blood cell counts, suggesting improved hematopoietic and immune function. Serum biochemistry showed elevations in aspartate aminotransferase, alanine aminotransferase, and alkaline phosphate at 15.0 – 20.0 g/kg PFE, though within physiological ranges. Importantly, PFE supplementation significantly reduced oxidative stress, evidenced by decreased superoxide dismutase, catalase, and malondialdehyde levels (P< 0.05), indicating enhanced systemic antioxidant capacity. Economic analysis revealed that despite a 96.73% increase in feed cost, 20.0 g/kg PFE increased net profit per fish by 136.8% and significantly improved the benefit-cost ratio. In conclusion, PFE is a viable nutraceutical for Nile tilapia. At a higher inclusion of 20.0 g/kg, PFE boosts growth, mitigates oxidative stress, and maximizes economic returns in sustainable aquaculture.