Effects of different levels of dietary nucleotide on growth performance, survival and liver enzyme activity of Caspian salmon (Salmo trutta caspius Kessler, 1877) juveniles

Caspian salmon (Salmo trutta caspius) juveniles were fed with dietary nucleotide levels of 0, 0.15, 0.25, 0.35 and 0.5% to investigate their effects on growth performance, survival rate and liver enzymes. Juveniles with an initial average weight of 12.26±0.001g were fed with the experimental diets for 60 days. The trial was carried out in 300 liter tanks each containing 35 fish which were fed with five meals a day at the rate of 34•5% of body weight. Statistical analysis was performed using One-way ANOVA. Results of the study showed that the addition of dietary nucleotide led to significant increase of body weight gain (BW), weight increase percentage (BWI), specific growth rate (SGR), protein efficiency ratio (PER), protein productive value (PPV) and feed intake but significant decrease of food conversion ratio (FCR) as compared to the control treatment (P0.05). The best value of growth improvement indices was observed at the dietary level of 0.25% nucleotide. Liver enzymes including AST, ALT and LDH at the level of 0.35% and ALP at the level of 0.25% were significantly lower than control treatment (P