Dietary protein requirements for juvenile sole Solea aegyptiaca (Chabanaud, 1927)

Abstract

ABSTRACThe present study was conducted to determine the dietary protein requirement for optimal growth performance and body composition of juvenile sole fish. Four diets were formulated with different protein levels (D40, D45, D50 and D55% crude protein). The silverside fish (Atherina boyeri) was added to the diets as local animal protein source and to enhance palatability of the test diets. Fish were fed the artificial diets as 2% of the fish biomass daily divided into two equal portions. Juvenile sole with an initial weight of (6.65±0.2g) were distributed as 40 juveniles in each triplicate tank, each of 1m 3 volume. The experimental period lasted 120 days after start. The results showed significant differences (P<0.05) in growth performance and feed efficiency between diets. The highest performances in terms of (Finial weight, Weight gain, Average daily gain, Specific growth rate, Condition factor, Feed conversion ratio, Protein efficiency ratio, Protein productive value and Hepatosomatic index) were obtained with the D55% CP, followed by D50%, without significance difference between them. However, fish fed D40% crude protein diet recorded less performance parameters. No significance difference (P<0.05) in whole body chemical composition (dry matter, crude protein, crude lipid and ash) were found between fish fed all experimental diets. However, slight increase in whole body lipid contents were recorded with D50%CP and D55%CP levels. The results of the present study indicated that, D55% crude protein level can be optimal for meeting the requirement of juvenile sole, Solea aegyptiaca without adverse effects on growth performance and feed efficiency.

Influence of several dietary protein and lipid levels on nutritional parameters and liver functions of Solea aegyptiaca juveniles

“…The highest feed utilization from FCR, PER, and NPU were obtained in diet (45/12%) protein to lipid levels, these results were in agreement with the values recorded in the same species (Solea aegyptiaca) by (Yones and Abdel-Hakim, 2011;Yones and Metwally, 2014), and Senegalese sole (Guerreiro et al, 2012).…”

“…In the present study, HSI values ranged from 1.0 to 1.2%, within the ranges were found in the same species (Yones and Abdel-Hakim, 2011;Yones and Metwally, 2014) and in other flatfish species (Hemre et al, 2003;Peres and Oliva-Teles 2005;Martins et al, 2007). HSI was not affected by dietary lipid levels, indicating that the liver was not the main site for body fat storage.…”

“…Thus, extensive efforts was achieved in studying the nutrient requirements of Sole, but some essential aspects of nutrition and physiology of this kind of fish are still missing. The fundamental assessment shows that Sole juveniles require 530g kg -1 dietary protein for the highest growth rate (Rema et al, 2008) and for Solea aegyptiaca 550g kg -1 (Yones and Abdel-Hakim, 2011). Otherwise, Guerreiro et al (2012) reasoned that dietary protein could be diminished from 550g kg -1 to 450g kg -1 , without influencing on fish performance by rising dietary lipid or carbohydrate level.…”

Incorporation of silverside meal to enhance diet palatability, growth performance and body composition of fingerlings sole Solea aegyptiaca (Chabanaud, 1927)

“…The present study indicated that, the growth performance parameters (final weight, daily gain, specific growth rate and condition factor) recorded an increase with PP75% inclusion level. The similar results were reported with Bonaldo et al, (2006) in juvenile Egyption Sole (Solea aegyptiaca), singalese sole fed plant protein based diet (Cabral et al, 2011) and animal protein based diets (Borges et al, 2009 andYones &Abdel-Hakim, 2011). The present results also show that the total replacement of silverside fish by plant protein based diet (PP100%) had a significant impact in the growth performance.…”

“…Less information is currently available for common sole (S. solea) nutrition (Piccolo et al, 2008). Recently information on nutritional needs of this flatfish juvenile stage has been attained and the protein requirement for good overall growth performance has been estimated to be 50-60% (Rema et al, 2008 andYones &Abdel-Hakim, 2011).…”