Digestibility of Soybean Cake, Niger Seed Cake and Linseed Cake in Juvenile Nile Tilapia, Oreochromis niloticus L.

Abstract

The apparent digestibility coefficients (ADCs) of dry matter, protein, lipid and energy for soybean cake (SBC), Niger seed cake (NSC) and linseed cake (LSC) were determined in juvenile Nile tilapia. The ADCs were determined using faeces collected with a settling chamber attached to the fish rearing tank. Test diets contained 70% reference diet and 30% test ingredients, with Cr 2 O 3 as an inert marker. All treatments were triplicated. There was significant difference in Apparent Dry Matter Digestibility (ADMD), Apparent Protein Digestibility (APD) and Apparent Energy Digestibility (AED) between the test ingredients. However, there was no significant difference (P>0.05) in Apparent Lipid Digestibility (ALD) between the test ingredients. Of the three ingredients tested, SBC produced the highest nutrient digestibility coefficients (P<0.05) while LSC showed the lowest nutrient digestibilities (P<0.05). The NSC, which was the cheapest plant protein source, was a good feed ingredient for Nile tilapia diets in terms of overall nutrient composition and acceptable digestibility coefficients enabling more accurate and economical feed formulation.