Digestibility Study and Nutrient Re-evaluation in Clarias gariepinus Fed Blood Meal-Rumen Digesta Blend Diet

Abstract

The nutrient utilization and digestibility of blood meal-bovine rumen digesta blend diet (BMBRD) fed to Clarias gariepinus burchell (1822) was assessed using 60 C. gariepinus juveniles with a view to confirming the digestibility and suitability of the BMBRD blend inclusion level in the diet of C. gariepinus for sustainable clariid production. Two set of three iso-nitrogenous experimental diets containing 35% crude protein were formulated with 0%, 25% and 50% BMBRD inclusion level to substitute the fishmeal component which was the primary protein source. The first set of experimental diet was designed to monitor the growth performance and feed utilization was fed fortnightly in duplicate to C. gariepinus juveniles, stocked in glass aquaria (60 cm x 30 cm x 30 cm) at 4% of the body weight in two instalments daily for 10 weeks, while the second experimental diet with 0.5% chromic oxide (Cr2O3) inclusion (as a digestibility marker) was prepared and fed to the fish for 7 days to determine to digestibility of the different BMBRD included diets. The obtained results showed that the fish fed 25% BMBRD included diet had significantly higher (p < 0.05) growth performance and feed utilization indices than the other experimental diets. Similar to observation in the growth performance and feed utilization indices, the fish fed BMBRD included diets had significantly higher (p < 0.05) protein and energy digestibilities than the fish fed 0% BMBRD (control diet) and the study confirmed that fishmeal can be partially replaced up to 25% BMBRD blend in C. gariepinus diet for optimum growth performance and feed utilization.