Effect of betafin and silymarin on hematological, serum biochemical parameters and growth of rainbow trout (Oncorhynchus mykiss)

Nutrition is critical in trout fish farming. In this regard، the use of medical plants to improve the growth and health of the liver is considred. This experiment was conducted to investigate the comparative effects of silymarin and betafin on the growth، some hematological and serum biochemical parameters of rainbow trout (Oncorhynchus mykiss). Five hundred and forty rainbow trouts (mean weight 35±2gr) were treated with control diet، 1gr silymarine powder per kg diet and 10gr per kg diet betafin during 60 days. Results showed that betafin significantly improved growth indices including weigth gain، specific growth rate، food conversion rate، protein efficiency ratio، daily growth rate، and survival rate compared with silymarin and control groups. RBC، Hb، PCV and globular indices showed no significant differences among three groups، nevertheless WBC increased in silymarine and betafin groups as compared to control. AST and ALT index except ALP index decreased significantly in betafin and silymarine groups. GSI index decreased in silymarine group as compared to others. Generally، it can be concluded that betafin improved growth and liver indices. Silymarine had no effect on growth، whereas it was effective in improving liver indices.