Brewery by-products (yeast and spent grain) as protein sources in gilthead seabream (Sparus aurata) feeds

• Published in: Aquaculture 2021-10, Vol.543, p.736921, Article 736921
• Main Authors: Estévez, A., Padrell, L., Iñarra, B., Orive, M., Martin, D. San
• Format: Article
• Language: English
• Subjects: Aquafeeds; Seabream; Spent grain; Spent yeast; Sustainability
• ISSN: 0044-8486; 1873-5622
• DOI: 10.1016/j.aquaculture.2021.736921

Two trials were conducted to test the effect of partial replacement of fishmeal by two brewery industry by-products, yeast and spent grain, included in isoproteic and isolipidic diets for gilthead sea bream (Sparus aurata), having in mind the commercial availability of these by-products. According to the obtained results, the inclusion of up to 30% brewers' spent yeast and 15% spent grain in the feed for gilthead seabream gave similar results in terms of growth, food conversion and fillet final composition to a feed with fish meal as the main protein source and show a protein digestibility of 89–95%. Taking into account that these by-products are produced in large quantities in Europe, they can be a potential source of protein to reduce the use of plant proteins or fish/animal by-products (trimmings) and increase the sustainability of both sectors, brewery industry and aquaculture. •Spent yeast and spent grain are highly digestible by seabream and can be included up to 30% and 15%, respectively.•Seabream growth and conversion using these by-products are similar to those obtained using a commercial feed.•Final fillet quality of gilthead seabream is similar to that obtained using a commercial feed.