Maintenance/submaximum feeding schedules for reducing solid wastes and improving feed conversion in aquaculture

Maintenance feeding (MF) followed by higher submaximum feeding was evaluated to reduce waste feed, fecal solids, and feed conversion ratios (FCRs) in aquaculture. Individually housed juvenile hybrid bluegills constituted a control and two treatments. Controls were fed daily at maximum consumption indicated by a lead control group. In feeding cycle 1 (FC1), treatments (T1 and T2) received 14 d of MF followed by higher submaximum feeding for 28 d at 75% (SM75) and 100% (SM100) of control ration. FC2 followed with 7 d of MF in T1 and T2, followed by 28 d of SM75 and SM100, respectively. Over the 77-d experiment, controls wasted 38.34% of feed provided; SM100 (10.64%) and SM75 (3.84%) wasted significantly less. Mean FCRs were controls (1.60), SM100 (0.98), SM75 (0.80); treatments were significantly below controls. Mean feces produced per feed consumed (%) were controls (5.54), SM100 (4.00), and SM75 (3.81). Treatments were significantly below controls by approximately 30%. Control and treatment SGRs did not differ; full catch-up growth occurred in treatments. Feeding hybrid bluegills on cycles of MF followed by higher submaximum feeding reduced waste feed and feces while improving FCRs. Maintenance/submaximum feeding may be applicable in aquaculture for reducing feed costs and improving effluent quality without reducing growth.