Impact of Graded Dietary Supplementation of Nucleotides Upon Zootechnical Performance and Biometric Indices of Gilthead Seabream (Sparus aurata) Fry

Abstract

Fish meal is considered as an ideal protein source for marine fish feed due to its nutritional value and high palatability for fish. Yet reducing the proportion of fish meal in marine fish feeds such as sea bream represents a challenge for fish nutrition experts, due to its economical and environmental benefits through reducing the cost of feed, reducing fishing stress on species that are used for fishmeal production as well as preserving important resources in the marine food network. The obstacle and challenges that facing nutrition researchers in regard to fishmeal alternatives, especially plant protein sources, are not only the adverse effects of the immune status and growth of fish, but also the efficiency of intestinal absorption. Hence, any practical and economically feasible approach that would be helpful to overcome these negative effects by using traditional or innovative feed additives become an important task. It is a well-established fact that nucleotides as functional nutrients improve the general condition of the body, growth, fat metabolism, as well as improving small intestine function, disease resistance and immune responses. Additionally, dietary inclusion of nucleotides has a sparing effect on the protein of the diet, as it may imitates the synthesis of amino acids. On the basis of the above-mentioned data, this study was conducted to investigate the effect of addition of the commercially available product Nucleoforce ™ as a source of nucleotides in the diets on growth, mortality rates, biomarkers, some indicators of oxidative stress, indicators of mitochondrial activity in hepatic tissues, gene expression via polymerase chain reaction, pregnancy and microbial equilibrium in the intestine as well as the content of various nutrients and amino acids profile in the body of sea bream fry.