Dietary short-chain fatty acid supplementation does not affect growth performance, metabolism, and oxidative status of European seabass (Dicentrarchus labrax) juveniles

Abstract

This study investigated the effects of dietary short-chain fatty acid (SCFA) supplementation, on growth performance, metabolism, and antioxidant status of European seabass juveniles. Six isoproteic (43 % crude protein) and isolipidic (18 % crude lipid) diets were formulated to include 0.25 and 0.50 % Sodium acetate (SA), Sodium propionate (SP), or Sodium butyrate (SB). A diet without SCFA supplementation was used as a control. The diets were fed to triplicate groups of European seabass juveniles (initial body weight of 15 g) for 56 days. The supplementation of SCFA in the diet had no impact on the growth, feed utilization, or body composition of seabass. In the intestine, gene expression of pyruvate kinase (pk) and glucokinase (gk), phosphoenolpyruvate carboxykinase (pepck), glucose facilitative carrier type 2 (glut2), and citrate synthase (cs) was lower in fish fed the SP0.50 diet than in the other groups. Moreover, fatty acid synthase (fas) gene expression was lower in fish fed the SA0.25, SA0.50, and SB0.25 diets than in the other groups. Further, catalase (CAT) and glutathione reductase (GR) activity and lipid peroxidation (LPO) levels showed no differences between groups. In contrast, glutathione peroxidase (GPX) activity was higher in fish fed the SP0.50 diet. In the liver, GR activity and LPO levels showed no differences between groups. In contrast, CAT activity was lower in all dietary treatments than in control, and GPX and G6PDH activity was lower in fish fed with the SB (0.25 and 0.50 %) diet than in the other diets. Overall, SCFA supplementation did not affect growth performance and feed utilization and only had minor effects on metabolism and antioxidant defense mechanisms.