Dietary effects of plant protein sources on the growth performance and feed utilization of Nile Tilapia, Oreochromis Niloticus, raised in concrete tanks

MSc. Dissertation 2018The study was conducted to evaluate practical diets for Nile tilapia Oreochromis niloticus composed of fishmeal, soybean meal, cotton seed cake meal and sunflower seed cake meal. Five isonitrogenous (30 g 100 g -1 ), isolipidic (10 g 100 g -1 ) and isoenergetic (18 kJ g -1 ) test diets were formulated. The control diet composed of fish meal (22%) and soybean meal (30%) as the major sources of protein. In the other test diets, fish meal was fixed at 5%, while inclusion of soybean meal, cotton seed cake meal and sunflower seed meal varied as follows; soybean meal 25 (SBM25), cotton seed cake meal 20 (CSM20), sunflower seed cake meal 20 (SFSM20) and blend diet (BLEND) contained CSM and SFSM were included at 10% and SBM at 5% respectively. A total of 120 fingerlings with an initial average weight of 13.96 ± 0.06 were stocked at a rate of eight fish per tank with a diameter of two meters and depth of one meter. Dietary treatments were in triplicates in complete randomized design. The experiment was conducted for six month and fish were weighed once a month to monitor growth and adjust feed ration. Data was analyzed using descriptive statistics and one way analysis of variance (ANOVA). There was significant difference in growth performance between control and other tested diets (p<0.05). Higher growth performance and feed utilization occurred in control diets followed by cotton seed cake meal, soybean meal, sunflower seed cake meal and finally blend diet. Cotton seed cake meal and sunflower seed cake meal diets were significantly more cost-effective than the control, BLEND and soybean meal diets (p