Effects of yeast nucleotide on growth performance, serum immune index and muscle composition of Ancherythroculter nigrocauda Yih & Wu

A ۵۰-day feeding trial was conducted to evaluate the effects of yeast nucleotide in diets on growth performance, serum immune indices and muscle composition of Ancherythroculter nigrocauda (mean initial body weight, ۲۳.۳۰±۰.۵۹ g). Seven isonitrogenous (approximately ۴۲.۷۶% crude protein) and isoenergetic (۱۷.۴۳ KJ g−۱ gross energy) experimental diets with varying levels of yeast nucleotide (۰[control], ۱۵۰, ۳۰۰, ۴۵۰, ۶۰۰, ۷۵۰ and ۹۰۰ mg kg−۱) were fed near to satiation to triplicate groups of fish. The results showed that the highest weight gain ratio (WGR), specific growth rate (SGR), protein efficiency ratio (PER), and best feed conversion ratio (FCR) were evident in fish fed ۴۵۰-۶۰۰ mg kg−۱ yeast nucleotide diet. The intramuscular protein and fat contents of data also supported the above level. The serum enzymes showed that activities of lysozyme (LZS) and superoxide dismutase (SOD) in fish increased first and decreased afterwards with the dietary nucleotide supplemental level increasing. The LZS activity in serum was found to be significantly (p<۰.۰۵) greater in fish fed yeast nucleotides at ۴۵۰-۷۵۰ mg kg−۱. The fish fed the diet with ۶۰۰ mg kg−۱ yeast nucleotide had higher SOD level (p۰.۰۵). Alkaline phosphatase (ALP) activity showed significantly (p<۰.۰۵) greater but continuous decrease with the increase in the levels of dietary yeast nucleotide. We therefore recommend dietary yeast nucleotide administration at (۴۵۰ – ۶۰۰ mg kg−۱) to promote growth, enhance immunity and intramuscular protein and fat content.

Keywords:

Ancherythroculter nigrocauda , Yeast nucleotide , Growth performance , Serum immune index , Muscle composition