Effects of Dietary Sodium Acetate on Growth Performance, Fillet Quality, Plasma Biochemistry, and Immune Function of Juvenile Golden Pompano (Trachinotus ovatus)

Abstract

Six isonitrongenous and isolipidic diets were formulated to feed 360 fish (mean initial body weight: <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" id="M1"> <a:mn>6.06</a:mn> <a:mo>±</a:mo> <a:mn>0.02</a:mn> </a:math> g) with graded levels of sodium acetate (SA1 (0), SA2 (250 mg/kg), SA3 (500 mg/kg), SA4 (1000 mg/kg), SA5 (2000 mg/kg), and SA6 (4000 mg/kg)) for 8 weeks. The results revealed that weight gain rate, specific growth rate, and feed intake of golden pompano were significantly increased in SA3 and SA4 treatments ( <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" id="M2"> <c:mi>p</c:mi> <c:mo>&lt;</c:mo> <c:mn>0.05</c:mn> </c:math> ). Dietary SA level significantly improved lipid contents and gumminess of muscle ( <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" id="M3"> <e:mi>p</e:mi> <e:mo>&lt;</e:mo> <e:mn>0.05</e:mn> </e:math> ). Supplement levels of dietary SA significantly influenced plasma biochemical parameters containing triglyceride, glucose, high-density lipoprotein cholesterol, complements, and immunoglobulin M ( <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" id="M4"> <g:mi>p</g:mi> <g:mo>&lt;</g:mo> <g:mn>0.05</g:mn> </g:math> ). Appropriate supplement levels of dietary SA significantly increased enzyme activities of hepatic superoxide dismutase and total antioxidant capacity and decreased malondialdehyde contents ( <i:math xmlns:i="http://www.w3.org/1998/Math/MathML" id="M5"> <i:mi>p</i:mi> <i:mo>&lt;</i:mo> <i:mn>0.05</i:mn> </i:math> ). Furthermore, appropriate SA levels downregulated the expression levels of Keap1, IL-8, TNF-α, and NF-κB genes and upregulated the expression levels of Nrf2 and TGF-β genes of the spleen ( <k:math xmlns:k="http://www.w3.org/1998/Math/MathML" id="M6"> <k:mi>p</k:mi> <k:mo>&lt;</k:mo> <k:mn>0.05</k:mn> </k:math> ). Excess SA caused negative effects for Trachinotus ovatus. The optimum supplement level of SA for juvenile golden pompano was evaluated to be 1423.67 mg/kg based on WGR.