The use of traditional aquafeed ingredients, such as fish meal and oil, remains a concern for the environmental sustainability of aquaculture. Therefore, significant research efforts are currently focused on identifying alternative protein sources using cost-effective and sustainable ingredients. Various alternative sources, such as plant or single-cell proteins, have been proposed as suitable substitutes. However, the utilization of new innovative feeds must prioritize fish health and welfare, as they directly impact production and consumer perception. This study evaluated the effects of a cost-effective and environmentally friendly innovative diet, which involved reducing fish meal content by 60% and replacing it with a blend of plant, yeast, and krill meal ingredients, on seabream growth, health, and welfare over a 135-day experiment. Various parameters were investigated, including growth, hematological, and biochemical indicators, along with monitoring of energy expenditure using accelerometer tags.
The results revealed no adverse effects of the innovative diet on survival and indicated slight improvements in growth performance among fish fed the innovative diet compared to those fed a commercial control diet (Fig. 1a). Data from accelerometer tags demonstrated higher energy expenditure in fish fed the innovative diet, potentially offset by the diet’s composition to maintain growth (Fig. 1b). Blood parameters associated with stress, immunity, and health showed no significant negative impacts from the innovative diet. On the contrary , fish fed the innovative diet exhibited higher levels of immunoglobulin M (Fig. 1c), potentially reflecting enhanced immune defenses. Overall, the innovative diet shows promise for seabream aquaculture, but further long-term studies are necessary.