Optimization of feeding management of juvenile Morone saxatilis in recirculating aquaculture systems for sustainable aquaculture

Feed represents the main production cost and one of the largest sources of environmental impact in intensive aquaculture systems, making it essential to develop feeding strategies that improve production efficiency and sustainability, particularly in recirculating aquaculture systems (RASs). This study evaluated moderate cyclic feed restriction strategies in juvenile Morone saxatilis over an 80-day period. A total of 168 fish (28.6 ± 2.9 g) were randomly distributed among 12 tanks and fed a commercial diet containing 45% crude protein. The treatments were divided into three groups: control: normal daily feeding; T1: a 25% reduction in feed for one day, followed by normal feeding the next day; and T2: a 25% reduction in feed for one day, followed by feeding 25% more than the control amount on the following day. The experiment lasted 80 days, during which only the T1 and T2 treatments alternated between 10 days of reduced feeding and 10 days of normal feeding. At the end of the experiment, biometric measurements were recorded, and tissue samples (muscle, liver, and visceral fat) were collected. No significant differences were observed among treatments for final weight, weight gain, or specific growth rate (p > 0.05). Although no statistically significant differences were detected, the T1 group showed slight improvements in feed conversion and feed efficiency, along with a lower visceral fat index. In addition, this group exhibited greater protein deposition (p < 0.05). These findings suggest improved nutrient utilization, indicating that this feeding strategy can maintain production efficiency without compromising growth. It can be concluded that a 25% reduction in feed quantity on alternate days can be adopted without compromising the growth of juvenile Morone saxatilis reared in RAS, provided that feeding is restored between restriction periods. Such strategies may reduce production costs and environmental impacts, contributing to more sustainable aquaculture systems.