Effect of Partial or Total Replacement Fish meal By Canola Protein Concentrate on Growth performance and Feed Utilization of Juvenile Oreochromis niloticus

An experiment was conducted to investigate the effect of replacing fish meal by 25, 50, 75and 100% canola protein concentrate meal (CPC) on growth performance, feed utilization, apparent nutrient digestibility and body composition of juvenile Oreochromis niloticus. Experimental diets were prepared to be isonitrogenous and isocaloric (34% CP; 19.4 kJ GE/ g DM). Three hundred fish (mean weight 43.6 ± 0.06 g) were cultured in plastic tank containing fresh water (28°C average temperature) for a period of 56 days. At the end of the experimental period, no significant differences were observed for weight gain (WG) and specific growth rate (SGR) among juvenile tilapia fed on control diet and diets containing CPC at level of 25%, 50% and 75%, respectively. Diet containing 100% CPC showed lower (WG) and (SGR). The data of feed utilization in terms of feed conversion ratio (FCR) showed the same trend of (SGR). However, protein efficiency ratio (PER) and protein retention efficiency (PRE) showed no differences among the fish groups fed on tested diets. No differences were found between control diet and diet containing 25% CPC in terms of apparent protein digestibility (APD). While, APD decreased with the fish groups fed diets containing 50, 75 and 100% CPC levels. However, Phosphors digestibility decreased staidly with increasing CPC levels. No significant differences (P<0.05) in whole fish body
composition. Slightly decrease in whole body ash content was detected. The results of this study show that juvenile Oreochromis niloticus can be cultured with feeding a diet containing 75% canola protein concentrate as fish meal replacer without any adverse effects on growth performance, feed utilization and body composition.