ابراهیم ستوده

This study was conducted to examine the effects of dietary crude oil on growth performance, plasma chemistry parameters and digestive histology of rainbow trout (Oncorhynchus mykiss) juvenile. Juvenile fish (with initial mean weight 15±0.5) were fed daily with pellets containing environmentally realistic concentrations of crude oil at 0 mg/kg diet (control), 50 mg/kg diet, 250 mg/kg diet and 500 mg/kg diet for 4 weeks. The results of this study showed that dietary crude oil had no significant effect on growth indices such as mean final weight, specific growth rate and feed conversion ratio (P>0.05). No mortality was observed throughout the 4-week experiment. The crude oil exposure did not significantly alter the plasma levels of total protein, glucose, direct bilirubin and liver enzyme activities (P>0.05). At the end of the experiment, histological observations of fish liver and intestine showed that there were no significant histological alterations between different treatments (P>0.05). In conclusion, this study showed that dietary crude oil up to 500 mg / kg diet had no significant effects on growth performance, health status and digestive histology structure of rainbow trout.