Serum Biochemical Responses of Nile Tilapia (Oreochromis niloticus) to Graded Dietary Levels of Detarium microcarpum Stem-bark Extract

Abstract

Plant-derived feed additives are increasingly investigated in aquaculture because of their potential to influence fish metabolism and physiological condition. Detarium microcarpum contains several bioactive phytochemical constituents; however, the effects of its stem-bark extract on serum biochemical responses in Nile tilapia (Oreochromis niloticus) remain insufficiently documented. This study therefore evaluated the effects of graded dietary levels of hydroethanolic D. microcarpum stem-bark extract on selected serum biochemical parameters in Nile tilapia. Serum biochemical responses of Nile tilapia (Oreochromis niloticus) to dietary Detarium microcarpum stem-bark extract were evaluated during a 90-day feeding trial conducted in Loumbila, Burkina Faso. A total of 180 fingerlings with an initial mean body weight of 7.49 ± 1.43 g were randomly distributed among 12 tanks at 15 fish per tank. Four diets were tested in triplicate: an unsupplemented control (RT) and diets containing 200, 300, or 400 mg of dried hydroethanolic extract per kg of feed (R1, R2, and R3, respectively). At the end of the trial, three fish were sampled from each tank, giving nine fish per treatment. Serum total protein, total cholesterol, triglycerides, and glucose were measured spectrophotometrically. Dietary effects were evaluated using a nested analysis of variance with tanks nested within treatments. No significant dietary effect was detected for total protein (P = 0.764), total cholesterol (P = 0.871), triglycerides (P = 0.510), or glucose (P = 0.749). Total protein ranged from 122.56 ± 42.17 to 152.67 ± 37.03 g/L, while total cholesterol ranged from 6.70 ± 1.34 to 8.15 ± 3.82 mmol/L. Triglycerides ranged from 1.96 ± 1.17 to 3.12 ± 1.67 mmol/L, and glucose ranged from 7.54 ± 8.12 to 12.18 ± 10.69 mmol/L. Under the experimental conditions, graded supplementation did not significantly alter the measured serum biochemical parameters. Greater tank replication and phytochemical characterisation of the extract are required to clarify potential metabolic responses.