Effects of dietary nucleotide on growth indices and intestinal morphology of rainbow trout (Oncorhynchus mykiss)

This experiment was conducted to examine the effects of dietary nucleotides on growth, and intestinal morphology of rainbow trout with mean initial weight of approximately 11.35 ± 0.01 g. Five diets with 0, 0.5, 1, 1.5 or 2 g of nucleotides (NT) Kg-1 diet were fed to rainbow trout for 8 weeks. Forty fish were kept in each of the triplicate tanks designed for every treatment group. Fish fed diets with 2 g and 1.5 g NT Kg-1 for 8 weeks had highest final weight and SGR and lowest in fish fed the NT-free control diet. After 8 weeks of feeding trial, there was a significant (P<0.05) decrease in FCR between the control and the groups fed diets with 1 g, 1.5 g and 2 g NT Kg-1. The highest length of intestine epithelium cells was observed in fish fed diets with 0.2 g NT Kg-1. The results suggest that dietary nucleotides exerted positive effects on growth indices and intestine morphology in rainbow trout.