Effects of Partial Substitution of Conventional Protein Sources with Duckweed (<i>Lemna minor</i>) Meal in the Feeding of Rainbow Trout (<i>Oncorhynchus mykiss</i>) on Growth Performances and the Quality Product

Abstract

Duckweed (Lemna minor) meal was included in the formulation of three experimental feeds (L1, L2, L3) for rainbow trout at 10%, 20%, 28% of the protein source, respectively. Increasing the duckweed inclusion, the other protein sources were adjusted to get isonitrogenous (41%) and isolipidic (20%) diets, as the control diet (LC). 540 fish (mean body weight 124.5 ± 0.7 g) were randomly allocated in 12 tanks divided equally among the four different diets. After 90 days, fish were weighed and the most important productive performances, fillet quality and fatty acid profile were determined. The final body weight in L1 (340.53 g) and L2 (339.42 g) was not different from LC (348.80 g); L3 trout significantly (p Lemna minor can be included in the feed for the rainbow trout without negative effects on the growth performances at 20% of the protein substitution.

Keywords

• sustainable fish feed
• aquatic plants
• alternative proteins
• on-growing phase