Supplementation of arachidonic acid rich oil in European sea bass juveniles (Dicentrarchus labrax) diets: effects on growth performance, tissue fatty acid profile and lipid metabolism

Abstract

The aim of this study was to evaluate the effects of increasing dietary arachidonic acid (ARA) levels (from 1 to 6% of total fatty acids) on European sea bass (Dicentrarchus labrax) juveniles' growth performance, tissue fatty acid profile, liver morphology as well as long-chain polyunsaturated fatty acids (LC-PUFA) biosynthesis, triglyceride and cholesterol synthesis and lipid transport. A diet with total fish oil (FO) replacement and defatted fish meal (FM) containing a 0.1-g ARA g diet was added to the experimental design as a negative control diet. Dietary ARA inclusion levels below 0.2 g ARA g diet significantly worsened growth even only 30 days after the start of the feeding trial, whereas dietary ARA had no effect on fish survival. Liver, muscle and whole body fatty acid profile mainly reflected dietary contents and ARA content increased accordingly with ARA dietary levels. Tissue eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) levels were positively correlated among them. Hepatic lipid vacuolization increased with reduced dietary ARA levels. Expressions of fatty acyl desaturase 2 and 3-hydroxy-3-methylglutaryl-coenzyme genes were upregulated in fish fed the negative control diet compared to the rest of the dietary treatments denoting the influence of ARA on lipid metabolism. Results obtained highlight the need to include adequate n-6 levels and not only n-3 LC-PUFA levels in European sea bass diets.

Influence of dietary n‐3 polyunsaturated fatty acids (PUFAs) on growth, PUFA composition and the expression of FAD6 and ELOV5 in pacific white shrimp ( Litopenaeus vannamei )

“…Growth in Litopenaeus vannamei increased with an increase in the dietary EPA and DHA content compared with animals fed a low n‐3 LC‐PUFAs diet (An et al., 2020; Araújo et al., 2019; Chen et al., 2015), but continue to increase dietary n‐3 LC‐PUFAs content did not further improve growth, and appeared to have a detrimental effect on survival of L.vannamei (An et al., 2020; González‐Félix et al., 2002). Similar results have been reported in rabbitfish Siganus canaliculatus (Xie et al., 2018), European sea bass Dicentrarchus labrax (Torrecillas et al., 2018), sea cucumber Apostichopus japonicus (Zhao et al., 2019) and common octopus Octopus vulgaris (Iglesias et al., 2007). D. labrax fed a diet with ARA levels below 0.2 g/kg displayed poor growth and survival only 30 days.…”

Oxidative status and intestinal health of gilthead sea bream (Sparus aurata) juveniles fed diets with different ARA/EPA/DHA ratios

“…As for ARA, the only available study indicates that increasing the dietary levels (0, 0.6, 1.14, 1.7%DM) has no effect on growth performance 10 . However, in European sea bass juveniles, dietary ARA levels below 0.2% reduced growth performance 11 .…”

Dietary arachidonic acid supplementation improves the growth performance and alleviates plant protein‐based diet‐induced inflammation in juvenile turbot ( Scophthalmus maximus L.)

“…In addition, dietary fatty acids can affect the cell membrane structure and function, cell signalling, and patterns of lipid mediator production by changing fatty acid composition of immune cell membranes (Philip & Calder, 2006; Yaqoob, 2003; Yaqoob & Calder, 2007). Dietary ARA supplementation enhanced the growth and antioxidant capacity in several fish species, such as Japanese seabass Lateolabrax japonicus (Xu et al., 2010) and European sea bass Dicentrarchus labrax (Torrecillas et al., 2018). Furthermore, dietary ARA has been shown to enhance the immune responses of cultured rabbitfish Siganus rivulatus (Nayak et al., 2017), which is consistent with the positive effects of ARA and its metabolites on human cells (Harbige, 2003; Surette et al., 1999).…”