Restricted feeding benefits the growth performance and glucose homeostasis of blunt snout bream Megalobrama amblycephala fed high-carbohydrate diets

Abstract

This study was conducted to investigate the effects of restricted feeding on the growth performance, glycolipid metabolism and glucose homeostasis of Megalobrama amblycephala fed a high-carbohydrate (HC) diet. A total of 240 fish (46.94 ± 0.04 g) were randomly assigned to four groups containing the satiation of a control diet (30 % carbohydrate) and three satiety levels (100 %, HC1; 80 %, HC2; and 60 %, HC3) of the HC diet (43 % carbohydrate) for 8 weeks. High carbohydrate levels remarkably decreased daily growth coefficient (DGC), growth rate per metabolic body weight (GRMBW), feed intake (FI) and the transcriptions of growth hormone (GH), growth hormone receptor (GHR), fructose-1,6-biphosphatase peroxisome (FBPase), proliferator-activated receptor α (PPARα) and carnitine palmitoyl transferase I (CPT I) compared to the control group, but intestinal enzymes activities, tissue glycogen and lipid contents, and the transcriptions of glucokinase (GK), pyruvate kinase (PK), sterol regulatory element-binding protein 1 (SREBP 1), fatty acid synthase (FAS) and acetyl-CoA carboxylase α (ACCα) showed an opposite trend. Furthermore, HC2 group obtained relatively high values of DGC, GRMBW, feed efficiency ratio (FER), intestinal enzymes activities and the transcriptions of GH, GHR, IGF-I, GK, PK, PPARα and CPT I. Meanwhile, the HC2 group enhanced the glucose tolerance of fish fed HC diet after glucose administration. Overall, the satiation level at 80 % benefited the growth rate, feed efficiency and glucose homeostasis of M. amblycephala fed a high-carbohydrate diet.