Dietary energy requirement of <i>C</i> juvenile at fixed crude protein and its effects on growth, nutrient performance, haematology and biochemical indices

Abstract

This study investigated the optimum dietary energy requirement of African catfish, Clarias gariepinus juveniles fed 35 % crude protein level and the effects on growth, nutrient performance, haematology and biochemical indices. The control diet A had 2800 kcal while, treatments B, C, D and E have 3000, 3200, 3400 and 3600 kcal energy inclusion respectively. Diets were fed to triplicate groups of eight catfish (51 ± 0.56 g) per tank twice daily to satiation for 8 weeks. Significant effects of graded energy levels across diets (p<0.05) on growth and nutrient utilization were recorded relative to diet A. The optimal dietary energy was within the range (3000 – 3200 kcal/Kg) on nutrients utilization and growth parameters. The least value (1.33 ± 0.17) and the best feed conversion ratio was recorded with fish fed 3000 kcal/kg while, the protein efficiency ratio was significantly high (p<0.05) at 3200 kcal/kg (52.80 ± 3.33). There was no significant difference (p>0.05) recorded across diets in the measured blood parameters and fish organs. Some biochemical parameters like total protein, albumin, cholesterol and high density lipoprotein were not significantly affected by dietary energy inclusion levels, other stress enzyme, like superoxide dismutase was significantly different between diet with diet A and diet E respectively. Though, diet A had the best estimated investment cost (N 48.30), diet C had the highest values for both net profit (N 50.68) and benefit cost ratio (N 1.79). Therefore, feed at 35 % CP would require between 3000 – 3200 kcal/Kg for optimum performance.

Keywords: Clarias gariepinus, Energy, Protein, Growth, Nutrient, Haematology, Biochemicals