Effect of Ethanolic Extract of Dill (Anethum graveolens) as a Food Additive on Growth Parameters and Activity of Lysozyme and Complement in Rainbow Trout (Oncorhynchus mykiss)

In this study, the effect of ethanolic extract of dill (graveolens Anethum) on growth and immunological parameters of rainbow trout fingerlings was evaluated (average initial weight of 12±0.32 g). A basal diet was supplemented with levels of 0 (control), 500, 1000, 1500 and 3000 mg ethanolic extract of dill kg-1 to formulate five experimental diets. After 56 days of feeding trial, fish fed diet with 1000 and 1500 mg kg-1 had the highest final weight compared to control but in terms of feed conversion ratio, specific growth ratio and protein efficiency ratio did not show a significant difference compared to control group. All treatments had a high survival rate and did not show significant differences with each other. The highest activity of lysozyme and complement was observed in the 1500 mg kg-1 treatment but did not significant difference compared to the control group (P>0.05). The results showed that concentrations of 1000 and 1500 mg kg-1 of ethanolic extract of dill increased the weight in these factors and the concentration of 1500 mg kg-1 treatment had better effect on immunity.