Effect of cinnamon (Cinnamomum verum) extract on productive traits, economic efficiency and blood biochemical parameters of rainbow trout (Oncorhynchus mykiss W.).

The aim of the present study was to evaluate the effect of the dietary cinnamon extract supplement on the survival rate, weight gain, feed conversion ratio (FCR), economic efficiency (ECR) and blood biochemical parameters of rainbow trout, cultivated in a recirculation system. One hundred and twenty rainbow trout were distributed in two experimental variants, with two replicates of 30 fish per each. The average initial live weight of fish from the control group (K) and experimental group (F) were 41.55±7.96 g and 41.48±7.95 g, respectively (P>0.05). The feed of fish from group F was supplemented with 1% powdered cinnamon extract, after lubricating the pellets with 5 ml sunflower oil per 100 g feed. Control group received the same amount of sunflower oil-lubricated feed. Fish were fed 3 times/daily with the diet, based on 3% of biomass. The trial period was 60 days. The inclusion of cinnamon extract had no significant effect on growth parameters of fish from two experimental groups (P>0.05). Survival rates were 100% from control and experimental groups. The final live weight of the rainbow trouts of the control and experimental groups was as followed: K – 117.25±19.15 g and F - 121.42±19.39 g, but the differences were not significant (P>0.05). The average weight gain of rainbow trouts in the control group was 75.70±11.53 g and it was lower than the values of fish from the experimental variant F with 5.59% (P>0.05). FCR of the control group was 1.08±0.03 and it was higher than that of the group F with 4.85% (P>0.05). The economic efficiency of feed with extract of cinnamon in the experimental group had better coefficient of economic efficiency 1.46, which is lower by 3.31% compared to the coefficient of the controls. Blood biochemical parameters of the fish from the two experimental groups did not differ substantially.