Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), College of Animal Science and Technology, Southwest University, Chongqing, 400715, People's Republic of China.
Liangping District Agriculture Commission, Chongqing, 400020, People's Republic of China.
Fish Physiol Biochem. 2020 Feb;46(1):125-134. doi: 10.1007/s10695-019-00705-7. Epub 2019 Sep 14.
The present study was conducted to investigate the effects of high dietary lipid levels on growth, metabolism, antioxidant capacity, and immune responses of largemouth bass. Fish (initial body weight 13.38 ± 0.11 g) were fed three isonitrogenous semi-purified diets containing 5%, 10%, and 20% lipid, respectively. The results indicated that fish fed 10% lipid diet showed significantly better final body weight, specific growth rate (SGR), protein efficiency ratio (PER), and feed conversion ratio (FCR) compared with that fed 5% lipid diet. Meanwhile, fish fed 20% lipid diet had a significantly higher viscera ratio (VR), hepatosomatic index (HSI), intraperitoneal fat ratio (IPF), and liver lipid content than those fed the other diets. Higher alanine aminotransferase (ALT) and aspartate transaminase (AST) activities, total cholesterol (TC), triglyceride (TG), free fatty acids (FFA), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) contents, and LDL-C/HDL-C value in plasma were recorded in fish fed 20% lipid diet, while higher insulin contents were obtained in fish fed 5% lipid diet. In addition, the highest carnitine palmitoyltransferase I (CPT1), AMP-activated protein kinase (AMPK), fructose-1,6-bisphosphatase (FBPase), and phosphoenolpyruvate carboxykinase (PEPCK) activities in the liver were also observed in fish fed 20% lipid diet. However, fish fed 20% lipid diet had a significantly lower superoxide dismutase (SOD) and catalase (CAT) activities and higher MDA contents in liver than those fed the other diets. The higher nitric oxide (NO) contents and inducible nitric oxide synthase (iNOS) activity in liver were recorded in fish fed 10% lipid diet. Moreover, the alkaline phosphatase (ALP), inducible nitric oxide synthase (iNOS) and lysozyme activities, and nitric oxide (NO) contents in plasma were higher in fish fed the 10% diets than the other groups. In conclusion, high dietary lipid levels could suppress growth performance and liver anti-oxidative capacity, and reduce immune responses of largemouth bass.
本研究旨在探讨高膳食脂质水平对大口黑鲈生长、代谢、抗氧化能力和免疫反应的影响。实验用鱼（初始体重 13.38±0.11g）分别投喂三种等氮半纯化饲料，其中脂质含量分别为 5%、10%和 20%。结果表明，与 5%脂质组相比，10%脂质组的鱼的终体重、特定生长率（SGR）、蛋白质效率比（PER）和饲料转化率（FCR）均显著提高。同时，20%脂质组的鱼的内脏比（VR）、肝体比（HSI）、腹腔脂肪比（IPF）和肝脂质含量均显著高于其他组。20%脂质组的鱼血浆中丙氨酸转氨酶（ALT）和天冬氨酸转氨酶（AST）活性、总胆固醇（TC）、甘油三酯（TG）、游离脂肪酸（FFA）、高密度脂蛋白胆固醇（HDL-C）、低密度脂蛋白胆固醇（LDL-C）含量和 LDL-C/HDL-C 值均显著升高，而 5%脂质组的鱼血浆胰岛素含量显著升高。此外，20%脂质组的鱼肝中肉碱棕榈酰转移酶 I（CPT1）、AMP 激活蛋白激酶（AMPK）、果糖-1,6-二磷酸酶（FBPase）和磷酸烯醇丙酮酸羧激酶（PEPCK）活性最高。然而，20%脂质组的鱼肝中超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性较低，丙二醛（MDA）含量较高。10%脂质组的鱼肝中一氧化氮（NO）含量和诱导型一氧化氮合酶（iNOS）活性较高。此外，10%脂质组的鱼血浆中碱性磷酸酶（ALP）、诱导型一氧化氮合酶（iNOS）和溶菌酶活性以及 NO 含量均高于其他组。综上所述，高膳食脂质水平会抑制大口黑鲈的生长性能和肝抗氧化能力，降低其免疫反应。
