At the end of the feeding trial, fish were starved for 24 h prior
to harvest. Fish were then anesthetized in diluted MS-222
(tricainemethanesulfonate, Sigma, USA) at the concentration of
100 mg/L. The total number and weight of fish in each cage were
then determined. Whole blood samples from four fish in each tank
were rapidly taken from caudal vessel into heparinized Eppendorf
tubes and were stored at −20 °C until analysis after individual
body weight measurement. These fish were later sampled for analysis
of viscera/body ratio and hepatosomatic index. Also, individual
liver and back muscle were quickly removed and stored at −20 °C
for subsequent analysis.