Protein – Sparing Activity of Lipid and Carbohydrate in the Giant African Mudfish, H. longifilis Diets

In two different experiments on lipid and carbohydrate requirement, H. longifilis was fed diets containing 13.68% to 24.66% of lipid, 17.00% to 20.86% of carbohydrates for 56 days. There was positive response in terms of growth of H. longifilis in the various diets fed in the experiments. There was significant variation (P 0.05) in the specific growth rate (SGR), food conversion ratio (FCR), protein efficiency ratio (PER), apparent net protein utilisation (ANPU) and percentage survival (PS) in the fish fed varying lipid levels. As for the fish fed varying levels of carbohydrates, there was no significant variation (P 0.05) in the SGR and FCR but there was significant variation (P 0.05) in the PER, ANPU and PS. The protein/lipid ratio was 1.58 while the protein/carbohydrate ratio was 2.22. These ratios are very important in the formulation of H. longifilis feed for optimal growth of fish in that protein is spared for growth while the lipid and carbohydrate portions of the diet are used for energy production.