Total replacement of marine oil by rapeseed oil in plant protein rich diets of juvenile lumpfish (Cyclopterus lumpus): Effects on growth performance, chemical and fatty acid composition

Abstract Lumpfish is used to control sea lice in open net-pen farming of Atlantic salmon, but little known about their nutritional requirements. The aim this study was investigate the effects replacing marine oil (MO) with rapeseed (RO), diets incorporating 50 % plant protein concentrates, on growth, chemical and fatty acid (FA) composition juvenile lumpfish. Four extruded diets, nearly iso-lipidic (14–15% DM) iso-nitrogenous (53–54% were produced either 10 MO (fish : krill constant proportion 2.3 1; Control), or replaced 25 %, 100 replacement RO give identified as RO25, RO50 RO100, respectively. Triplicate groups fish (7 ± 0.18 g) fed experimental ad libitum during 6 weeks. No significant found growth parameters, specific rate, hepatosomatic index (HSI), visero-somatic index, condition factor (CF), whole body when by RO. Monounsaturated acids (MUFA) polyunsaturated (PUFA) body, liver muscles also not affected MO. Total substitution significantly reduced performance, CF, increased HSI, crude lipid liver, accompanied deposition. At end experiment, saturated (SFA), PUFA, n-3 FA eicosapentaenoic (EPA), docosahexaenoic (DHA) muscles, decreased (p