On day 42 of the feeding trial, all fish were fasted for 24 h, anesthetized
with ethanol at 50 mg l−1, counted, and individually weighed. A pooled sample
of ten fish from each replicate tank was randomly collected and stored
at −20◦C for whole-body analysis. Proximate composition analyses (moisture,
crude protein, total lipid, fiber, and ash) of fish, feed ingredients, and
experimental diets were carried out according to the Association of Official
Analytic Chemists (AOAC 1998). Nitrogen-free extract (NFE) was estimated
on a dry-weight basis by subtracting the percentages of crude protein, lipids,
crude fiber, and ash from 100%.
The following equations were used to estimate growth and feed
utilization: