日粮中裂殖壶藻油配伍外源性EPA对草鱼幼鱼脂肪酸组成、FAD、ELO基因表达及脂质代谢的影响  

Effects of Schizochytrium sp.oil combined with exogenous EPA on fatty acid composition,FAD and ELO gene expression and lipid metabolism of juvenile Ctenopharygodon idella

作　　者：邢君霞 吉红[1] 李汉东 肖芬芬 袁想通 XING Junxia;JI Hong;LI Handong;XIAO Fenfen;YUAN Xiangtong(College of Animal Science and Technology,Northwest A&F University,Yangling 712100,China)

机构地区：[1]西北农林科技大学动物科技学院,陕西杨凌712100

出　　处：《水产学报》2021年第10期1642-1656,共15页Journal of Fisheries of China

基　　金：蓝色粮仓科技创新重大专项(2019YFD0900200)。

摘　　要：摄食含有裂殖壶藻硬脂油日粮的草鱼可能通过节省DHA合成所需的能量和促进脂解作用供应能量以减少蛋白质分解的共同作用下,刺激蛋白质沉积,获得比摄食鱼油更好的生长效果。为探究草鱼日粮中应用富含DHA的裂殖壶藻硬脂油后是否需要配伍EPA及其可能机制,实验配制5组等氮等能日粮饲养草鱼[(22.70 g±0.80)g]49 d,分别以鱼油(F-O);藻油硬脂(S-O);藻油硬脂(DHA)∶EPA=3∶2(SE1-O);藻油硬脂(DHA)∶EPA=1∶1(SE2-O);EPA(E-O)提供5组饲料中的0.52%n-3长链多不饱和脂肪酸(LC PUFA)。结果显示:(1)增重率(WG)、特定生长率(SGR)及饲料系数(FCR)在各组间均无差异;(2)S-O组肌肉粗蛋白含量显著高于E-O组;(3)S-O组肌肉DHA含量显著高于F-O组、SE1-O组和E-O组;(4)动脉粥样硬化指数在各组间无显著差异,SE2-O组血栓形成指数显著高于F-O组,S-O组和SE2-O组胆固醇血症指数显著低于F-O组;(5)E-O组的腹腔脂肪细胞显著大于F-O组和SE1-O组,且甘油三酯水解酶(ATGL)和肉碱棕榈酰转移酶(CPT1)转录水平显著下调;肌肉中的脂肪酸去饱和酶(FAD)转录水平在E-O组显著高于S-O组,脂肪酸延长酶(ELO)转录水平在S-O组显著下调。研究表明,裂殖壶藻油单独或配伍EPA使用对草鱼生长、n-3 LC PUFA含量及脂肪组织水解无显著影响。仅以EPA为n-3LC PUFA来源时,会减弱脂肪组织的水解并降低肌肉粗蛋白的含量。日粮中高水平的DHA会减弱机体合成LC PUFA的能力。相对于EPA,草鱼可能更需要DHA,生产中可以单独使用裂殖壶藻油,而无需配伍EPA。The grass carp(Ctenopharyngodon idella)dietary Schizochytrium sp.stearin oil may show better growth performance than dietary fish oil by saving energy required for de novo synthesis of DHA,promoting lipolysis energy supply and inhibiting protein catabolism.The purpose of this study was to investigate whether DHA-rich Schizochytrium sp.stearin oil needs to be compatible with EPA and its possible mechanism.Equipped with five groups of iso-nitrogen and isoenergetic diets and fed grass carp(22.70 g±0.80 g)for 49 d.The 0.52%n-3 long-chain polyunsaturated fatty acid(LC PUFA)of the diets were provided with fish oil(F-O);Sc stearin oil(SO);stearin oil(DHA)∶EPA=3∶2(SE1-O);stearin oil(DHA)∶EPA=1∶1(SE2-O);EPA(E-O),respectively.The results showed:1)There was no difference in the weight gain rate(WG),specific growth rate(SGR)and feed conversion ratio(FCR)among all the groups;2)The content of crude protein in muscle of S-O group was significantly higher than those of E-O group;3)the content of DHA in muscle of S-O group was significantly higher than that of F-O group,SE1-O group and E-O group;4)there was no significant difference in atherogenicity index among the groups,the thrombogenicity index of SE2-O group was significantly higher than that of F-O group,the hypocholesterolemic/Hypercholesterolemic ratio in S-O group and SE2-O group was markedly lower than those in F-O group;5)the adipose size of intraperitoneal fat in E-O group was notably higher than those in F-O group and SE1-O group,the adipose TAG lipase(ATGL)and carnitine palmitoyltransferase 1(CPT1)mRNA levels in E-O group were apparently down-regulated;in muscle,the fatty acid desaturase(FAD)mRNA level was markedly higher in E-O group than that in S-O group,the fatty acid elongase(ELO)mRNA level was obviously down-regulated in S-O group.Studies have shown that the use of Sc oil alone or in combination with EPA had no significant effect on growth,n-3 LC PUFA content and lipid hydrolysis of adipose tissue of grass carp.When EPA was the sole source of n-3 LC P

关 键 词：草鱼 裂殖壶藻 EPA 长链多不饱和脂肪酸 

分 类 号：S963[农业科学—水产养殖]