Effects of restricted feeding regimes on greenhouse gas emission, production and economics of tilapia (Oreochromis mossambicus) monoculture in pond

This study evaluated the effects of different feeding regimes on water quality parameters, fish growth, feed performance, economic returns and greenhouse gas emissions (GHGs) in Oreochromis mossambicus monoculture. Three treatments were applied viz. T1: regular feeding (twice daily); T2: feeding off 1 day/week and T3: feeding off 2 days/week, each with two replications. Significant variations (P<0.05) were found in water quality parameters such as dissolved oxygen (4.59±0.24 to 6.31±0.22 mg/L), pH (5.51±0.08 to 6.60±0.01), CO2 (4.59±0.24 to 6.31±0.22 mg/L) and total dissolved solids (520.68±3.74 to 554.57±3.78 mg/L), while temperature remained within the optimal range (29.06 to 29.320C). Growth performance was highest in T1 (final weight: 249.65 g; SGR: 2.08%) and lowest in T3 (190.63 g, SGR: 1.74%). FCR ranged from 1.67 to 1.87, and survival rate from 80.50% to 87.50%. Net profit was highest in T2 (454322.78 BDT/ha) followed by T1 and T3, indicating 16.7% increase over T1 and 50.2% over T3. Cost-benefit ratio was also highest in T2 (0.70), suggesting economic viability of moderate feed deprivation. Importantly, GHGs emissions were maximum in T1 (8.75 kg/ha/year), and minimum in T3 (6.62 kg/ha/year), showing a 24.3% reduction with intermittent feeding. These findings highlight that moderate feed restrictions (T2) can optimize production performance, enhance profitability, and reduced environmental impact, offering a sustainable strategy for tilapia aquaculture. This dual benefit approach supports economic efficiency and environmental sustainability, aligning with global goals for climate-smart aquaculture.