Agroecology 7 min

New alternative ingredients and genetic selection are the next game changers in rainbow trout nutrition: a metabolomics appraisal

The addition of alternative ingredients (insects, microalgae, yeast) to plant-based feeds and the use of a line selected for its growth performance with plant-based feeds improve the growth performance and metabolic functioning of farmed rainbow trout.

Published on 29 April 2024

illustration New alternative ingredients and genetic selection are the next game changers in rainbow trout nutrition: a metabolomics appraisal

The formulation of sustainable fish feeds based on plant ingredients supplemented by alternative ingredients to plant (insect, micro-algae, yeast) and genetic selection of fish for plant-based diets were tested on rainbow trout in two separate experiments.

Plant-based diets and corresponding diets supplemented with an ingredient mix: insect, micro-algae and yeast in Experiment A, and insect and yeast in Experiment B were compared to commercial-like diets. In experiment A, the mix-supplemented diet was successful in compensating the altered growth performance of fish fed their respective plant-based diet compared to those fed the commercial diet, by restoring feed conversion.

In experiment B, the selected line demonstrated improved growth performances of fish fed mix-supplemented and plant-based diets compared to the non-selected line. Metabolomics demonstrated a plasma compositional stability in fish fed mix-supplemented and basal plant-based diets comprising
an amino acid accumulation and a glucose depletion, compared to those fed commercial diets. The selected line fed mix-supplemented and commercial diets showed changes in inositol, ethanol and methanol compared to the non-selected line, suggesting an involvement of microbiota. Changes in plasma glycine-betaine content in fish fed the mix-supplemented diet suggest the ability of the selected line to adapt to alternative ingredients.


This work was supported by the FUI NINAqua project (New Ingredients for New Aquaculture Foods) and MetaboHUB. Simon Roques was funded by "Phileo by Lesaffre" and the ANRT.



Scientific contact

Benoit Fauconneau Nutrition, Metabolism, Aquaculture


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