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

Abstract

The present study was conducted to determine the effects of use silverside meal to enhance palatability, growth performance and body composition of fingerlings sole fish fed on plant based diets. Two sources of plant protein (soybean and corn glutein meal) were replacing silverside meal in tested diets. Five diets were formulated with different inclusion levels of plant protein based diets (PP0, PP25, PP50, PP75 and PP100%). The silverside fish (Atherina boyeri) was added to the diets as local animal protein source, replacer to fish meal and to enhance palatability of the test diets. Fingerlings sole with an initial weight of (8.65±0.2g) were distributed 100 fingerlings in each tank, with a volume of 2m 3. Fish were fed on the artificial diets as 3% of the fish biomass daily divided into two equal portions. Fish were organized in triplicate groups/diet and 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 (Final weight, Weight gain, Average daily gain, Specific growth rate, Condition factor, Feed conversion ratio, Protein efficiency ratio, Net protein utilization and Hepatosomatic index) were obtained with the PP75, PP0, PP50 and PP25%, without significance difference between them. However, fish fed on PP100 % diet showed significant differences (P<0.05) with decreased growth performance and feed efficiency compared to the other tested diets. Non-significant differences (P<0.05) in the whole body chemical composition (dry matter, crude protein, crude lipid and ash) were found between fish fed on all experimental diets. The results of the present study indicated that PP75% inclusion level, which reduce silverside meal and increase alternative plant protein sources in fingerlings sole, Solea aegyptiaca diet can be used without negative effects on growth performance and feed efficiency.