Effect of Feed Pellet Diameter on Growth of Rohu Juveniles in Flow-Through Aquaculture System

Three iso-nitrogenous feeds, having different pellet diameter viz, 2.5 mm (T-I), 3.5 mm (T-II) and 5 mm (T-III) were used for feeding rohu juveniles for 5 weeks. The flow rate per cistern was maintained at 31/s, rohu juveiles (av. wt. 85.0 g) was stocked with a stocking density of 60/m² in each. The net biomass gain, specific growth rate (SGR) and feed conversion efficiency were 3.20±0.15, 3.88±0.13 and 7.95±0.57 (kg/10m²); 0.20±0.06, 0.24±0.08 and 0.48±0.04; 3.62±0.17, 3.05±0.10 and 1.70±0.16, respectively, in treatment I, II and III. The net biomass gain and SGR were significantly (P<0.01) higher in T-III. The water quality parameters were within normal range in all the three treatments. It was concluded that 5 mm size of pelleted feed performed better for feeding rohu juveniles in flow-through system.