Researchers at the Alfred Wegener Institute and the Technologie-Transfer-Zentrum Bremerhaven have taken a major step forward in their search for an alternative to fishmeal, an expensive and ecologically problematic fish feed ingredient.
As part of a research project on the optimisation of lupinemeal for aquaculture funded by the German Federal Ministry of Food and Agriculture (BMEL), the scientists demonstrated that fish feed can consist of up to 50 percent of lupinemeal without negatively impacting the growth and feed conversion rates of fish. The liver health of fish is adversely affected only if the amount of lupine exceeds 50 percent.
In this study, AWI biologists Christina Hörterer, Monika Weiss and Sinem Zeytin fed feed mixes with different lupine ratios to European Seabass (Dicentrarchus labrax). The result: The predators accepted the vegetable feed, utilised the feed very well and grew just as fast as the control group that received fishmeal. What's more, tasters thought the seabass fed with lupinemeal was just as palatable as the fish fed with fishmeal. "We therefore consider lupinemeal a sustainable and significantly cheaper alternative to fishmeal. We believe that lupinemeal has great potential in aquaculture", says Christina Hörterer.
Commercially available fish feed for predators such as salmon or seabass currently contains about 20 percent soy as well as fishmeal. Large areas of rainforest are cut down in South America for the cultivation of soy. Some of the plants are genetically modified, which is why both their cultivation and their processing are ecologically problematic and highly controversial.
Lupines, on the other hand, grow in Central Europe and are often grown to be used as green manure. The leguminous plants have the highest protein content of native grain legumes. "The fish feed industry using lupinemeal as its protein source can increase agrobiodiversity on European fields, promote the regional sourcing of raw materials and offer a sustainable alternative to fishmeal", says Dr Matt Slater, head of the aquaculture research group at the Alfred Wegener Institute.
In a next step, in order to make lupinemeal marketable as a feed ingredient, the manufacturing process has to be optimised. This includes trials that test the use of protein concentrates made from lupines in fish feed. The German Federal Ministry of Food and Agriculture (BMEL), funds this research project on protein plant strategy via the Federal Office for Agriculture and Food (BLE).