Evaluation of Ground - Sundried Cassava Leaf Meal as Protein Source for Nile Tilapia Oreochromis niloticus (L) Juvenile’s Diet

Abstract

Ground and sun dried cassava leaf meal (CLM) was evaluated as a protein source for Oreochromis niloticus juveniles. Biochemical analyses, digestibility study and growth trial were undertaken. Biochemical analyses showed that grinding followed by sun drying resulted into 60% reduction of hydrogen cyanide while saponins, phenols, tannins and phytic acid were slightly affected. Crude lipid and crude fibre contents were also reduced. Digestibility trial showed that CLM has low apparent digestibility of protein (44.5%) and energy (44.2%). Increased inclusion of CLM from 0, 15, 30, 45 to 60 g100 g-1 of total dietary crude protein resulted into a significant reduction of growth, nutrient utilisation and whole body composition after an eight week growth trial. SGR declined from 3.17% in fish fed CLM0 to 1.15% in those fed CLM60. Similarly, FCR increased from 1.45 in fish fed CLM0 to 5.02 in those fed CLM60. Whole body lipid declined from 8.29% fed CLM0 to 2.61% in those fed CLM60. Histopathological examination of liver and small intestine did not show any changes that could be linked to dietary treatment. Therefore, there is need to improve digestibility of CLM in order to realise its potential as a protein source in Nile tilapia diets.

Key words: Nile tilapia, cassava leaf meal, digestibility, nutrient utilisation