EFFECT OF SAVORY EXTRACT SUPPLEMENTATION ON SOME PRODUCTIVE TRAITS AND ECONOMIC EFFICIENCY OF COMMON CARP (Cyprinus carpio L.)

The purpose of this study is to evaluate the effect of a dietary savory extract supplement on the survival rate, growth performance, feed conversion ratio and economic efficiency of common carp ( Cyprinus carpio L.) reared in a recirculation system. Thirty-two carps were allotted into two experimental variants, each of them comprising two replications with 8 fish in a group. The average initial live weight of fish from both replications from the control group (CG) and experimental group (EG) was 866.56±113.99 g and 866.81±119.10 g, respectively (p>0.05). They were kept in concrete tanks with efficient water volume of 0.8 m 3 , elements of the recirculation system. Carps were fed pelleted carp feed with 25% crude protein, produced with pellet size of 6 mm. The feed of fish from the EG was supplemented with 1% powdered savory extract, after lubricating the pellets with 5 ml sunflower oil per 100 g feed. Control carp received the same amount of sunflower oil-lubricated feed. The daily ration of fish from both replications was 1.8% of their live weight. The experiment duration was 45 days. Survival rates during the experiment showed 100% survival in carps, supplemented with 1% savory extract as well as in control fish . The average individual weight gain of carps from the two EG replications ( supplemented with 1% savory extract ) was 154.63±28.39 g, which was higher than that of controls by 57 . 1 8% (Table 3), as the differences were statistically significant ( p< 0.0 01 ). At the end of the trial, the analysis of consumed feed amount showed that feed conversion ratio in the group supplemented with 1% savory extract was 2.25±0.43 e.g. by 67.11% lower than that of control group, as the differences were statistically significant (p<0.001). The group that received 1% savory extract exhibited better economic conversion ratio (1.98), by 42.42% lower than that of the non-supplemented group.