A research team has explored new strategies to cut fishmeal content in sea bream feed without compromising the fish’s growth performance, immunity, or overall well-being—a challenging mission, yet feasible.
Under the Horizon 2020 FutureEUAqua project, researchers substituted up to 60% of the fishmeal with a blend of plant-based ingredients, yeast (Saccharomyces cerevisiae), and krill. This formula not only aims to lessen environmental impact but also to cut costs.
The trials, conducted at Fondazione COIPSA ETS in Bari, Italy, revealed that fish fed the experimental diet achieved a slightly higher specific growth rate than those on standard commercial feed, while feed conversion and protein efficiency ratios were similar between both groups.
The findings, published in Aquaculture Research, showed that cortisol and other stress indicators did not negatively impact the fish’s health, suggesting the diet does not compromise their welfare.
As for immunity, fish on the novel experimental diet exhibited higher levels of Immunoglobulin M (IgM), pointing to potential enhancement of humoral immunity, which involves antibodies in the circulatory system. This effect is likely due to the inclusion of krill in the diet.
In terms of behaviour, researchers observed increased swimming activity, indicating a greater energy expenditure. This was consistent with elevated prealbumin plasma levels, an indicator of energy metabolism.
Despite these promising results, further research is necessary to understand how these innovative feeds can support the sustainability of aquaculture on a commercial scale. Future studies should include testing in commercial settings.
Reference:
Alfonso, S., Toomey, L., Fiocchi, E., Manfrin, A., Boscarato, M., Vasilaki, P., Zupa, W., Bertazzo, V., Bégout, M.-L., Spedicato, M. T., Mente, E., Nengas, I., Lembo, G., & Carbonara, P. (2024). Growth performance, immune characteristics, and health and welfare of gilthead seabream (Sparus aurata) fed a tailor-made environmentally sustainable diet formulated using novel ingredients. Aquaculture Research.
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