2.2. Experimental design
L. rohita fingerlings (mean bodyweight 11.1 ± 0.07 g) were
acclimatised to laboratory conditions in 500-L quarantine tanks at
26 ± 2 C for 2 weeks and were fed a basal diet. Approximately 20%
of the water in all tanks was exchanged daily and 100% of the water
was exchanged weekly. Basic physioechemical parameters of the
water were measured weekly [26]. Oxygen and ammonia concentrations
were 6.1e7.3 mg L1 and 0.03e0.06 mg L1, respectively,
and pH ranged 7.0e8.0 throughout the study period.
Fish were randomly divided into five experimental groups, with
three replicates in each group. Tank capacity was 200 L, and each
tank contained 20 fish. Fish were fed one of the five diets (basal
diet, G1, G2, G3, or G4) for 60 days, at 3e5% of body weight for three
times (0800, 1300, and 1800) daily. The amount of feed consumed
was determined by daily recovery of excess feed, which was then
adjusted every 15 days by batch weighing after 24 h of starvation.