Modulatory effect of air-dried Moringa oleifera leaf meal on growth and physiology of African catfish Clarias gariepinus (Burchell, 1822)

Abstract

An experiment was conducted to investigate the effect of air-dried Moringa oleifera leaf meal (MLM) on the growth and physiology of African catfish. Air-dried MLM was incorporated into a diet D1 (19.64MJ/kg) at 0, 2, and 6% resulting in three diets. Each diet in the D1 group was fed to African catfish fingerlings (13.35 ± 0.02) at 5% body weight in triplicate group for 56 days. Weight gain was significantly (p<0.05) higher in the control diet (0% MLM) compared to MLM-based diets. White blood cell (WBC) counts were significantly (p<0.05) higher in fish-fed 2% MLM relative to those of the control and 6% MLM. Red blood cell (RBC), Haemoglobin (Hb), Mean cell volume, mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration decreased with increasing MLM inclusion levels. Higher levels of RBC and Hb were related to higher weight gain. Levels of liver enzymes- alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) decreased with increasing MLM inclusion levels. Decreases in ALT, AST, and ALP were not different (p<0.05) among the treatments. Serum total protein, albumin, and globulin levels increased in MLM-based treatments, 2% MLM were similar (p<0.05) to those of the control treatment while 6% MLM was different. Low dietary inclusion of air-dried MLM boosts WBC and increases serum proteins with no negative effect on liver enzymes. Regression of weight gain on MLM levels suggests an optimum range of 0.5 – 1% dietary inclusion can sustain growth making it a suitable feed additive.