Dietary Choline Supplementation Modulates Growth Performance and Protein Metabolism by Promoting Glucose and Lipid Catabolism in Chinese Perch (Siniperca chuatsi)

An 8-week trial was conducted to investigate the effects of choline on the growth of Chinese perch (85.57 ± 0.54 g) with dietary choline supplementation at 0 (P0), 400 (P1), 800 (P2), 1600 (P3), 3200 (P4), and 6400 mg/kg (P5). Protein efficiency ratio and protein retention value (PRV) were higher in the P1-P4 groups than in the P0 group (<i>p</i> < 0.05). Compared to the P0 group, weight gain rate and specific growth rate (SGR) increased in the P2 and P3 groups (<i>p</i> < 0.05). The orexigenic gene <i>agrp</i> expression level rose in the P2-P4 groups (<i>p</i> < 0.05). The expression level of the lipolysis-related gene <i>hsl</i> or <i>pparα</i> was elevated in the P2 and P4 groups (<i>p</i> < 0.05). Proteolysis-related gene (<i>ampd</i>, <i>mafbx</i>, and <i>murf1</i>) expressions decreased in the P1-P4 groups, while <i>tor</i> and <i>gk</i> gene expressions increased in the P2 and P3 groups (<i>p</i> < 0.05). Broken-line analysis indicated that the optimal choline supplementation level for Chinese perch is 788.38 mg/kg based on SGR and 851.04 mg/kg based on PRV. The results demonstrate that moderate dietary choline supplementation enhances growth performance by promoting glucose and lipid catabolism and inhibiting protein catabolism in Chinese perch.