Making aquafeeds more sustainable: Regional Legumes for Salmon Aquafeeds

Atlantic salmon (Salmo salar). Photo: https://en.wikipedia.org/wiki/Atlantic_salmon

Most of the world‘s rising demand for fish and shellfish is met by aquaculture. High protein fish feeds are generally produced with substantial amounts of fish meal – which is expensive and unsustainable. The possibilities for developing a sustainable approach to aquaculture are exciting. We have an opportunity to shift aquafeed's dependence on fish-based ingredients to a fish-free product that is based on legume protein, and create a more sustainable aquafeed with less environmental impact. Our findings provide new insight into how we can get there.

Legumes are being tested as sustainable, local replacements for fishmeal in feeds for important European aquaculture species like White leg shrimp and European seabass. In our last experiment, we formulated aquafeeds with lupin (L. angustifolius) and faba bean (Vicia faba) products for the Atlantic salmon Salmo salar.

Nine experimental diets containing Lupin and Faba bean products were designed to meet the requirements of S. salar at grow out (after smoltification), i.e. equal energy content, protein and amino acid profile, lipid and fatty acid composition, vitamins and minerals. Feeding experiments were conducted over 60 days in a land-based recirculating aquaculture system, with 36 separate tanks each stocked with 16 fishes. Experimental diets were fed in 4 replicates. At the end of the experiment samples for immunological analyses were taken and are being analysed.

What we found out is that an inclusion rate of 35% of Faba bean and Lupin were accepted without any negative impact on growth or immune capacity of the Atlantic salmon.

Major challenges for aquaculture are to sustain resources used for production, such as feed ingredients, and the reduction of feed costs. Knowing that lupins are 1/3 of fish meal price, we are happy to present the successful integration of legumes into commercial feeds.