日粮中裂殖壶藻渣对多鳞白甲鱼生长、脂代谢及健康的影响

Effects of defatted Schizochytrium sp. in diet on the growth, lipid metabolism and health of Onychostoma macrolepis

摘要:

为探究裂殖壶藻渣作为饲料原料对多鳞白甲鱼的生长性能、脂代谢及健康状况的影响，配制5种等氮等脂饲料，分别添加0(DS0)、30(DS3)、60(DS6)、90(DS9)和120 g/kg (DS12)的裂殖壶藻渣，饲喂养殖于室内循环水系统的180尾多鳞白甲鱼[(9.00±0.55) g，12尾/缸]，共56 d。结果显示：(1)增重率(WG)、特定生长率(SGR)及饲料系数(FCR)在各组间无显著差异；(2) DS9组和DS12组的肥满度(CF)、肝体比(HSI)、腹脂指数(IFI)、肝脏和腹脂甘油三脂(TG)含量均显著低于对照组；(3) DS6、DS9和DS12组肌肉中DHA含量、∑n-3 LC PUFA (n-3长链多不饱和脂肪酸) 含量、n-3/n-6 PUFA比例、胆固醇血症指数(h/H)和血脂质量指数(FLQ)显著高于对照组，而动脉粥样硬化指数(AI)和血栓形成指数(TI)均显著低于对照组；(4)所有处理组肝脏的脂肪酸合成酶(FAS)和乙酰辅酶A羧化酶1(ACC1)的mRNA表达水平显著低于对照组；DS6、DS9和DS12组腹腔脂肪组织的乙酰辅酶A羧化酶2(ACC2)和甘油三酯水解酶(ATGL)的mRNA表达水平显著高于对照组；(5)所有处理组血清中超氧化物歧化酶(SOD)活性显著高于对照组，丙二醛(MDA)含量显著低于对照组。研究表明，日粮中添加90 g/ kg的裂殖壶藻渣可通过影响脂代谢相关基因的表达降低多鳞白甲鱼腹腔脂肪和肝脏脂肪蓄积，并提升其肌肉营养价值，增强机体抗氧化能力。

Abstract:

The purpose of this study was to investigate the effects of defatted Schizochytrium sp. as a feed ingredient on the growth performance, lipid metabolism and health status of the indigenous fish, Onychostoma macrolepis. 0 g/kg (DS0), 30 g/kg (DS3), 60 g/kg (DS6), 90 g/kg (DS9) and 120 g/kg (DS12) of defatted Schizochytrium sp. were added to the five isonitrogenous and isolipid feeds, respectively. 180 Onychostoma macrolepis (9.00 g±0.25 g/ind., 12/tank) were fed and cultured in an indoor circulating water system for 56 days. The results showed that: 1) There were no significant differences in weight gain rate (WG), specific growth rate (SGR) and feed conversion ratio (FCR) among the groups (P>0.05); 2) The condition factor (CF), hepatosomatic index (HSI), intraperitoneal fat body index (IFI), and triglyceride (TG) content of liver and intraperitoneal fat in DS9 and DS12 groups were significantly lower than those in the control group (P<0.05); 3) The DHA content, ∑n-3 LC PUFA (n-3 long-chain polyunsaturated fatty acid) content, n-3/n-6 PUFA ratio, cholesterolemia index (h/ H) and lipid quality index (FLQ) were significantly higher than those in the control group, while the atherosclerosis index (AI) and thrombosis index (TI) were significantly lower than those in the control group (P<0.05); 4) The mRNA expression levels of fatty acid synthase (FAS) and acetyl-CoA carboxylase 1 (ACC1) in the liver of all treatment groups were significantly lower than those in the control group (P<0.05); The mRNA expression levels of acetyl-CoA carboxylase 2 (ACC2) and triglyceride hydrolase (ATGL) were significantly higher than those in the control group (P<0.05); 5) The activity of superoxide dismutase (SOD) in the serum of all treatment groups was significantly higher than that of the control group, and the content of malondialdehyde (MDA) was significantly lower than that of the control group (P<0.05). Studies have shown that adding 90 g/kg of defattedSchizochytrium sp. to the diet may significantly reduce the accumulation of abdominal fat and liver fat in Onychostoma macrolepis by affecting the expression of genes related to lipid metabolism, and improve its muscle nutritional value and enhance the body's antioxidant capacity.