为研究大豆黄酮在大菱鲆幼鱼中的营养生理作用,本实验在以鱼粉为主要蛋白源的基础饲料中添加不同剂量的大豆黄酮(0、5、10、20和100 mg/kg)来配制5种等氮等脂的实验饲料,并通过12周的投喂养殖实验评估饲料中不同剂量的大豆黄酮对大菱鲆幼鱼生长性能、消化酶活力、抗氧化力以及肠道结构的影响。结果表明:与对照组相比,饲料中添加不同剂量的大豆黄酮对大菱鲆幼鱼的存活率(98.89%~100.00%)、终末体质量(21.24~24.42 g)、特定生长率(1.81~1.98%/d)、饲料效率(1.01~1.11)、摄食率(1.43~1.51%/d)及形体指标均没有产生显著性影响;饲料中添加大豆黄酮显著降低了大菱鲆幼鱼鱼体的粗蛋白(15.41%~15.59%)和粗脂肪(3.19%~3.93%)含量,但对鱼体的水分(77.41%~79.70%)和灰分(3.46%~3.81%)含量未产生显著性影响;饲料中添加10~100 mg/kg大豆黄酮显著提高了大菱鲆幼鱼的胰蛋白酶活力(35.26~40.66 U/g prot),但胃蛋白酶(31.75~49.56 U/mg prot)、肠蛋白酶(10.00~14.79U/mg prot)、胃淀粉酶(0.10~0.25 U/mg prot)和肠淀粉酶(0.05~0.17 U/mg prot)的活力在各处理组间没有显著性差异。饲料中添加5、10和20 mg/kg的大豆黄酮显著降低了血清丙二醛(10.67~11.17 nmol/mL)的含量,并显著提高了大菱鲆幼鱼血清超氧化物歧化酶(51.05~53.36U/mL)和谷胱甘肽过氧化物酶(551.40 U/mL)的活力;饲料中添加不同浓度的大豆黄酮对大菱鲆幼鱼后肠肠道结构完整性没有显著性影响,但10~20 mg/kg大豆黄酮显著促进了肠道组织结构的发育和成熟,提高了大菱鲆幼鱼后肠肠绒毛的高度(391.26~401.48μm)。研究表明,大豆黄酮(5~100 mg/kg)对大菱鲆的生长没有显著性的影响,但饲料中适量的大豆黄酮(10~20mg/kg)可以显著提高大菱鲆幼鱼的消化酶活力和抗氧化能力,并促进肠道绒毛的发?
A 12-week feeding trial was conducted to evaluate the effects of dietary daidzein on growth performance,activities of digestive enzymes,anti-oxidative ability and intestinal morphology in juvenile turbot( Scophthalmus maximus L.) [Mean initial body weight( 4. 63 ± 0. 01) g]. Five isonitrogenous and isolipidic diets( crude protein,50%; crude lipid,10. 5%) were formulated to contain 0,5,10,20,and 100 mg /kg daidzein,respectively. The feeding trial was conducted in an in-door flowing seawater system.Triplicate groups of 30 fishes were hand-fed to apparent satiation twice daily. After the feeding trial,growth performances,physiological and biochemical parameters were analyzed. The results showed that the growth performances and feed utilization of fish,including final weight( 21. 24-24. 42 g),specific growth rate( 1.81-1. 98 % /d),feed efficiency( 1. 01-1. 11) and feed intake( 1. 43-1. 51 % /d),were not significantly affected by dietary daidzein supplementation( P〈0. 05). Similar results were also found in condition factor( 1. 83%-1. 99%),hepatosomatic index( 0. 72%-0. 97%) and viscerosomatic index( 4.19%-4. 68%)( P〈0. 05). However,the addition of 5-100 mg/kg daidzein in diet significantly decreased the protein( 15. 41%-15. 59%) and lipid( 3. 19%-3. 93%) contents of fish whole body( P〉0. 05) without effects on the moisture( 77. 41%-79. 70%) and ash( 3. 46%-3. 81%) contents( P〉0. 05).The trypsin( 35. 26-40. 66 U /g prot) activity in turbot was significantly( P〈0. 05) improved by 10-100 mg /kg dietary daidzein whereas the activities of pepsin( 31. 75-49. 56 U /mg prot),intestinal caseinolytic( 10.00-14.79 U/mg prot),intestinal amylase( 0.05-0.17 U/mg prot) and gastric amylase( 0.10-0.25 U /mg prot) showed no significant difference among all treatments( P〈0. 05). Compared to the control,addition of 5-20 mg /kg daidzein in diet significantly increased the activities of serum superoxide dismutase( SOD)( 5