Authors: Paula Sarmiento, Pedro L. Castro, Rafael Ginés

Published in animals, 2025, 15(13), 1913

Summary

As aquaculture expands, its sustainability depends on strategies that improve resource efficiency. This study evaluates the long-term effects of replacing extractive marine-based ingredients with sustainable alternatives, combined with feeding restrictions and genetic selection in gilthead seabream (Sparus aurata). High-growth selected and non-selected fish were fed either to apparent satiety or under restricted feeding (85% and 65% of satiety). Two diets were tested: a control diet based on fishmeal and fish oil, and an alternative diet based on sustainable protein and oil sources. The results show that the alternative diet is not only feasible but also enhances fillet quality by improving the balance between omega-3 and omega-6 fatty acids and fillet firmness. The selected fish showed superior growth and adapted better to the alternative diet and feeding restrictions. Feeding at 85% satiety improved fillet quality by reducing lipid accumulation and avoiding muscle stress. These findings suggest that combining an alternative diet with novel sustainable ingredients, genetic selection, and moderate feed restriction is a promising strategy to improve sustainability and product quality of gilthead seabream farming.