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1.
王岩 《应用生态学报》2003,14(2):237-240
将72尾杂交罗非鱼分别养在12个水槽内,每个水槽内养6尾大小不同的鱼(A、B、C、D、E、F),其中鱼A的初始体重为62.69±1.46g,B为56.48±1.30g,C为50.75±1.19g,D为35.56±1.18g,E为31.05±0.88g,F为27。35±0.95g(平均值±标准误).在4周实验中,实验鱼分别被停食或每天按体重1.5%、3.0%和饱食水平投喂.鱼的特定生长率(SGR)和食物效率(FE)先随食物水平增加而增加,当食物水平超过鱼体重的3.0%后,继续增加投喂量,SGR不再升高而FE明显下降.按体重1.5%投喂的鱼SGR和终体重个体间变异较大.对鱼A而言,食物水平超过体重1.5%后对其SGR无显著影响,但对鱼F而言,食物水平对SGR影响较大.结果表明,杂交罗非鱼的生长和个体生长分化与食物条件和初始体重有关,当食物水平超过体重的3.0%后,鱼的SGR较高,个体生长分化相对较轻.  相似文献   

2.
以n-3 HUFA含量为0.16%、1.27%、2.36%和3.47%的4种人工配合饲料(D1~D4)及天然饲料(冰鲜杂鱼,D5)饲养花尾胡椒鲷(Plectorhynchus cinctus)雌亲鱼一周年,通过比较各饲料组亲鱼的产卵量、卵和仔鱼质量以及各月份的血浆性类固醇激素水平,研究n-3 HUFA对生殖性能及性类固醇激素水平季节性变化的影响。平均每kg雌鱼的产卵量、卵受精率、仔鱼存活率、开口仔鱼体长等,D2和D3组与D5组相近,但D1和D4组显著低于D5组;饲料中n-3 HUFA含量对血浆17β-雌二醇(E2)和睾酮(T)水平的季节性变化规律无明显影响,但亲鱼性腺发育与成熟时期的E2和T水平.D1和D4组较D5组显著降低。n-3 HUFA含量对亲鱼离体卵泡E2和T的分泌也有一定影响:D4组卵泡E2的基础分泌很少;绒毛膜促性腺激素(HCG,100IU/mL)可刺激D2-D5组卵泡分泌E2和T,但D1组卵泡对HCG无反应。结果提示,花尾胡椒鲷亲鱼饲料中n-3 HUFA的适宜含量为1.27%-2.36%,不足或过高对亲鱼的生殖性能均有不利影响;通过影响性类固醇激素的产生可能是饲料中n-3 HUFA含量影响鱼类生殖性能的机制之一。  相似文献   

3.
南方鲇的营养学研究:饲料中大豆蛋白水平对生长的影响   总被引:23,自引:4,他引:19  
以初始体重为 2 3 .78± 0 .0 9g的南方鲇幼鱼为实验对象 ,在室内循环水养殖系统中进行为期 6周的生长实验。以大豆蛋白分别替代 0 %、1 3 %、2 6 %、3 9%、5 2 %和 6 5 %的鱼粉蛋白 ,配制成 6种等氮 (粗蛋白为 48%)、等能 (总能 2 0 KJ/ g)的饲料 ,用于探讨饲料中鱼粉蛋白与大豆蛋白的不同比例对南方鲇生长及饲料转化率的影响。实验在 2 7.5± 0 .2℃水温条件下进行 ,溶氧维持在 5 mg/ L以上 ,光照周期为 1 4L:1 0 D。实验结果表明 ,当大豆蛋白分别替代1 3 %、2 6 %和 3 9%的鱼粉蛋白时 ,3组之间的特定生长率 (SGR)的差异不显著 (P>0 .0 5 ) ,但均显著高于 5 2 %和 6 5 %替代水平 (P<0 .0 5 )。其中 1 3 %和 2 6 %的替代水平的特定生长率(SGR)显著高于对照组 (P<0 .0 5 ) ;3 9%替代水平的特定生长率 (SGR)与对照组之间差异不显著 (P>0 .0 5 ) ;而 5 2 %和 6 5 %替代水平的特定生长率 (SGR)则显著低于对照组 (P<0 .0 5 )。饲料转化率 (FCE)、蛋白质效率 (PER)和蛋白质累积率 (PPV)分别在各处理组之间的差异关系与特定生长率 (SGR)在各组之间的变化相类似。因此 ,本文提出南方鲇饲料中大豆蛋白替代 3 9%的鱼粉蛋白是适宜的 ,过量的添加将影响南方鲇的生长及饲料转化率。通过分析认为大豆蛋白影响南方鲇生  相似文献   

4.
实验旨在研究饲料缬氨酸水平对军曹鱼(Rachycentron canadum)[初始体质量为(40.90.8) g]鱼体脂肪含量、血浆生化指标和肝脏脂肪代谢基因表达的影响。在基础饲料中梯度添加晶体缬氨酸, 配制出缬氨酸含量分别为1.26% (缺乏组)、2.21% (适量组)和2.62% (过量组)3种等氮等脂饲料, 饲喂养殖在海水浮式网箱的军曹鱼10周, 每天饱食投喂2次。结果表明, 缬氨酸缺乏组的军曹鱼鱼体和肌肉脂肪含量显著低于缬氨酸适量组和过量组(P0.05)。肝脏脂肪含量随着饲料中缬氨酸含量从1.26%升高到2.21%而显著升高(P0.05), 然后随之而逐渐下降(P0.05)。军曹鱼血浆总蛋白和总胆固醇含量在缬氨酸缺乏饲料组显著低于其他各处理组(P0.05)。饲料缬氨酸水平对军曹鱼血浆谷草转氨酶和谷丙转氨酶均无显著影响(P0.05)。军曹鱼肝脏固醇调节元件结合蛋白-1 (sterol regulatory element binding protein-1, SREBP-1)基因表达水平和肝脏脂肪酸合成酶(FAS)表达量, 均随着饲料缬氨酸水平增加而显著升高(P0.05)。军曹鱼肝脏过氧化物酶体增殖物激活受体(peroxisome proliferator activated receptor, PPAR)表达量在缬氨酸适量组, 显著低于过量组(P0.05), 而与缺乏组差异不显著(P0.05)。而随着缬氨酸含量升高, 肉毒碱棕榈酰转移酶-1 (CPT-1, Carnitine palmitoyltransferase-1)表达量逐渐下降(P0.05)。总之, 饲料缺乏缬氨酸可减少军曹鱼鱼体脂肪积累。饲料中缬氨酸水平对军曹鱼鱼体脂肪沉积的影响, 可能是通过调控脂肪合成和-氧化相关基因表达而实现的。  相似文献   

5.
实验旨在确定2种规格军曹鱼的脂肪需求, 同时探索不同含量的脂肪对2种规格军曹鱼体组成及血清生化指标的影响。以鱼粉、酪蛋白和豆粕为蛋白源, 鱼油为脂肪源, 通过添加不同配比的鱼油配制6种脂肪水平[5.27%、8.22%、10.81%、14.26%、17.32%和20.94% (占干重)]的等氮实验饲料。挑选(38.24±0.30) g (25尾/箱, 40 g规格)和(529.17±5.67) g (10尾/箱, 500 g规格)2种规格的军曹鱼, 置于浮式网箱(1.3 m×1.3 m×2.5 m)中每日饱食投喂2次, 分别进行10周和8周的摄食生长实验。结果表明:随着饲料脂肪含量的增加, 2种规格军曹鱼特定生长率(SGR)和饲料效率(FER)均先上升再下降, 而脏体比(VSI)与肥满度(CF)均显著升高(P<0.05)。另外, 随着饲料脂肪水平的增加, 40 g规格的军曹鱼肝体比(HSI)、鱼体、肝脏和肌肉脂肪含量均显著升高, 鱼体水分和蛋白含量显著下降(P<0.05), 而500 g规格的军曹鱼各处理之间未发现显著差异(P>0.05)。随着饲料脂肪水平的增加, 40 g规格的军曹鱼, 血清总甘油三酯(TG)、血清总胆固醇(TC)、高密度脂蛋白-胆固醇(HDL-C)、低密度脂蛋白-胆固醇(LDL-C)及血糖(Glu)含量显著增加(P<0.05), 而500 g规格的军曹鱼, 除血清TG在各处理之间呈现出显著差异外(P<0.05), 其余指标在各处理之间均未发现显著差异(P>0.05)。综上所述, 以SGR和FER为评价指标, 40 g左右规格的军曹鱼脂肪需求量为13.97%—14.16%, 500 g左右规格的军曹鱼脂肪需求量为13.18%—13.47%。  相似文献   

6.
选择健康的翘嘴鲌(Culter alburnus)为试验鱼,以红鱼粉为蛋白源,配制5个蛋白水平的等能、等必需氨基酸(EAA)平衡关联度的半精制饲料,又以豆粕替代鱼粉,大豆蛋白分别替代不同水平的鱼粉蛋白,配制5个EAA关联度的等蛋白、等能的半精制饲料,探讨饲料蛋白对鱼类生长和内分泌激素等的影响。结果表明:饲料蛋白水平对翘嘴鲌的特定增重率(SGR)具有显著影响(P〈0.05),40.89%饲料蛋白组的SGR显著高于31.04%、35.51%饲料蛋白组(P〈0.05),但与46.62%和50.33%饲料蛋白组没有显著性差异(P〉0.05)。血清T3水平与饲料蛋白水平正相关(P〈0.05)。血清GH水平与饲料蛋白水平和生长负相关(P〈0.05),血清IGF—I水平与饲料蛋白水平和生长正相关(P〈0.05)。适宜蛋白水平通过提高翘嘴鲌血清T,和IGF—I的水平来调控生长。当大豆蛋白分别替代54.0%的鱼粉蛋白时,翘嘴鲌的SGR与对照组差异显著(P〈0.05)。翘嘴鲌血清T1与饲料大豆蛋白对鱼粉蛋白的替代量负相关(P〈0.05)。40.5%和54.0%替代组的血清GH显著高于对照组(P〈0.05),且与饲料中豆粕对鱼粉替代水平正相关(P〈0.01),与生长负相关(P〈0.05)。血清IGF—I与饲料中大豆蛋白对鱼粉蛋白替代量负相关(P〈0.05),与生长正相关(P〈0.05)。大豆蛋白的替代亦通过对内分泌激素的影响来调控生长。  相似文献   

7.
以初始体重为(137.5±0.4)g的大黄鱼Larimichthys crocea为实验对象,在海水浮式网箱中进行为期8周的摄食生长实验,研究饲料中糖水平对其生长、饲料利用、血液生化指标和糖代谢酶活力等的影响,以确定大黄鱼的饲料糖需求量。实验饲料按等氮(粗蛋白质45%)等能(18 kJ/g)设计,糖含量分别为1.75%、6.67%、13.64%、21.15%、26.69%和32.25%。结果表明随着饲料糖水平的升高,大黄鱼特定生长率(SGR)先升高后降低,当糖含量为26.69%时,SGR达最大值,显著高于糖含量为1.75%、6.67%、13.64%和32.25%处理组(P < 0.05)。饲料效率(FER)和蛋白质效率(PER)均在糖含量为13.64%-21.15%时显著高于其他处理组(P < 0.05)。随饲料中糖水平的升高,全鱼粗脂肪含量显著降低,在糖含量为32.25%时降至最低(10.56%),显著低于其他处理组(P < 0.05)。肝体比和肝糖原含量均随饲料糖水平的升高而显著升高(P < 0.05),在糖含量为32.25%时达到最大值,显著高于糖含量为1.75%和6.67%处理组(P < 0.05)。随饲料糖水平的升高,血浆甘油三酯和胆固醇水平均显著降低(P < 0.05),而血糖水平不受饲料糖含量的影响(P>0.05)。大黄鱼血清溶菌酶、脂蛋白脂酶和肝脂酶活性均随饲料糖水平的升高显著降低(P < 0.05),而肠淀粉酶活性表现为先升高后降低,在糖含量为26.69%时,酶活力达到最大值。随饲料糖水平的升高,大黄鱼肝脏己糖激酶活性先上升后下降,在糖含量为21.15%时达到最大值,显著高于糖含量为32.25%处理组(P < 0.05),而丙酮酸激酶活力在糖水平为32.25%时达到最大值,显著高于糖含量为1.75%和6.67%处理组(P < 0.05)。用二次多项回归模型拟合特定生长率和饲料糖水平的关系,得到大黄鱼饲料中最适糖含量为22.7%。  相似文献   

8.
为研究不同棕榈油替代水平对黄颡鱼生长性能、肌肉脂肪酸组成、形体指标和肝脏组织结构的影响, 实验采用5组等氮(400 g/kg)等脂(100 g/kg)等能(15.70 MJ/kg)饲料饲喂黄颡鱼[(16.15±0.04) g], 对照饲料以鱼油鲶豆油1鲶2混合为脂肪源, 实验饲料以棕榈油分别替代10、25、40和55 g/kg的混合脂肪源。经过8周的养殖实验, 结果表明棕榈油替代水平对黄颡鱼的摄食量、终末体重、特定生长率、饲料效率和蛋白沉积率未产生显著性的影响(P>0.05), 但是上述指标均呈现先升高后略微下降的趋势, 并在25 g/kg替代组达到最大值。背肌肌肉中亚油酸和n-3HUFA含量随着棕榈油替代水平的上升而显著下降(P<0.05), 但n-3/n-6比值随着棕榈油替代水平的上升而显著上升(P<0.05), 棕榈油替代水平对各组黄颡鱼的肥满度和脏体比未产生显著性的影响(P>0.05), 但是55 g/kg棕榈油替代水平组肝体比显著高于25 g/kg棕榈油添加组(P<0.05), 且55 g/kg棕榈油替代水平组黄颡鱼的肝脏组织出现细胞肿胀, 细胞核移位, 肝血窦和脂肪细胞数量明显增多等不良影响。据上所述: 对于黄颡鱼幼鱼, 棕榈油可以替代25 g/kg的混合脂肪源(鱼油鲶豆油=1鲶2)不影响鱼体生长性能并且在一定程度上改善了背肌肌肉脂肪酸组成。  相似文献   

9.
以体重为(4.86±0.02)g的虹鳟稚鱼为实验对象,在室内循环水养殖系统中进行为期90d的生长实验。用1000 U/kg植酸酶预处理大豆分离蛋白,然后以预处理的大豆分离蛋白(Soy protein isolate,SPI)分别替代0、20%、40%、60%、80%和100%的鱼粉蛋白,配制成6种等氮(粗蛋白为44.97%)、等能(粗脂肪为13.42%)的饲料,以评估饲料中鱼粉替代量对虹鳟生长、体组成、消化率及氮磷排泄的影响。90d的养殖实验结果表明,大豆分离蛋白替代鱼粉对虹鳟生长性能和饲料利用率产生显著的影响(P<0.05)。当大豆蛋白替代水平由0增加到40%时,虹鳟的特定生长率(SGR)显著提高,随着饲料中SPI替代水平由40%增加到100%时,虹鳟的SGR显著降低(P<0.05),在S0、S20和S60试验组之间差异不显著(P>0.05)。增重率(WGR)和蛋白质效率(PER)分别在处理组之间的差异关系与特定生长率(SGR)在各组之间的变化趋势相类似;当大豆蛋白分别替代40%时,其饲料系数(FCR)显著低于其他替代组(P<0.05),当替代量超过40%后,随着替代水平的增加,FCR显著增加(P<0.05)。随着替代水平由0升高到100%,磷排泄显著降低,与之相反的是,磷沉积率显著升高。随着替代水平由0升高至40%,氮排泄逐渐降低,当替代水平由40%升高至100%,氮排泄逐渐升高,随着替代水平升高至40%,氮沉积率升高。试验证明,大豆分离蛋白替代量达到40%时,虹鳟的生长及饲料转化率达到最佳,而高比例的SPI对虹鳟的生长性能和饲料效率产生负面影响。  相似文献   

10.
在基础配合饲料中添加(4%)不同脂肪源[鱼油、猪油、豆油、花生油、混合油I(鱼油:豆油=1:1)、混合油Ⅱ(鱼油:猪油:豆油:花生油=1:1:1:1)]配制成6组实验饲料,对体重(2.23±0.05)g的管角螺幼螺进行60d的饲养试验。结果表明,鱼油组摄食率(34.10g/d·ind·10^3)、增重率(64.33%)和特定生长率(0.79%)最高,与混合油I组没有显著差异(P〉0.05),并显著高于其他各组(P〈0.05),最低的为猪油组;肝体比没有显著差异(P〉0.05),猪油组最高(1.33),混合油I组最低(1.22);饲料转化率和存活率没有显著差异(P〉0.05);鱼油组粗蛋白含量(肌肉:18.35%;肝脏:17.55%)显著高于猪油组、豆油组、花生油组和混合油Ⅱ组,猪油组(2.96%)和鱼油组(2.86%)肝脏粗脂肪含量显著高于其他各组(P〈0.05),水分和灰分没有显著差异(P〉0.05);鱼油组EPA(肌肉:4.44%;肝脏:5.89%)和DHA(肌肉:4.53%;肝脏:5.65%)含量,n-3/n-6(肌肉:1.57;肝脏:1.69)均最高.与混合油I组没有显著差异(P〉0.05)。从人体健康和生产角度来说,以混合油I作为管角螺脂肪源不但可以得到较好的生长效果,还可以节约饲料成本。  相似文献   

11.
12.
13.
Rat liver fatty acid-binding protein (FABP) is a 14.3-kDa cytosolic protein which binds long chain free fatty acids (ffa) and is believed to participate in intracellular movement and/or distribution of ffa. In the studies described here fluorescently labeled ffa were used to examine the physical nature of the ffa-binding site on FABP. The fluorescent analogues were 16- and 18-carbon ffa with an anthracene moiety covalently attached at eight different points along the length of the hydrocarbon chain (AOffa). Emission maxima of all FABP-bound AOffa were found to be considerably blue-shifted with respect to emission of phospholipid membrane-bound AOffa, suggesting a high degree of motional constraint for protein-bound ffa. Large fluorescence quantum yields and long excited state life-times indicate that the FABP-binding site for ffa is highly hydrophobic. Analysis of rotational correlation times for the FABP-bound AOffa suggest that the ffa are tightly bound to the protein. Variation of the quantum yield with attachment site suggests that the carboxylic acid group of the fatty acyl chain is located near the aqueous surface of the FABP. The rest of the ffa hydrocarbon chain is buried within the protein in a hydrophobic pocket and is particularly constrained at the midportion of the acyl chain.  相似文献   

14.
The fatty acid transport function of fatty acid-binding proteins   总被引:38,自引:0,他引:38  
The intracellular fatty acid-binding proteins (FABPs) comprise a family of 14-15 kDa proteins which bind long-chain fatty acids. A role for FABPs in fatty acid transport has been hypothesized for several decades, and the accumulated indirect and correlative evidence is largely supportive of this proposed function. In recent years, a number of experimental approaches which more directly examine the transport function of FABPs have been taken. These include molecular level in vitro modeling of fatty acid transfer mechanisms, whole cell studies of fatty acid uptake and intracellular transfer following genetic manipulation of FABP type and amount, and an examination of cells and tissues from animals engineered to lack expression of specific FABPs. Collectively, data from these studies have provided strong support for defining the FABPs as fatty acid transport proteins. Further studies are necessary to elucidate the fundamental mechanisms by which cellular fatty acid trafficking is modulated by the FABPs.  相似文献   

15.
16.
Intersubunit transfer of fatty acyl groups during fatty acid reduction   总被引:2,自引:0,他引:2  
Fatty acid reduction in Photobacterium phosphoreum is catalyzed in a coupled reaction by two enzymes: acyl-protein synthetase, which activates fatty acids (+ATP), and a reductase, which reduces activated fatty acids (+NADPH) to aldehyde. Although the synthetase and reductase can be acylated with fatty acid (+ATP) and acyl-CoA, respectively, evidence for acyl transfer between these proteins has not yet been obtained. Experimental conditions have now been developed to increase significantly (5-30-fold) the level of protein acylation so that 0.4-0.8 mol of fatty acyl groups are incorporated per mole of the synthetase or reductase subunit. The acylated reductase polypeptide migrated faster on sodium dodecyl sulfate-polyacrylamide gel electrophoresis than the unlabeled polypeptide, with a direct 1 to 1 correspondence between the moles of acyl group incorporated and the moles of polypeptide migrating at this new position. The presence of 2-mercaptoethanol or NADPH, but not NADP, substantially decreased labeling of the reductase enzyme, and kinetic studies demonstrated that the rate of covalent incorporation of the acyl group was 3-5 times slower than its subsequent reduction with NADPH to aldehyde. When mixtures of the synthetase and reductase polypeptides were incubated with [3H] tetradecanoic acid (+ATP) or [3H]tetradecanoyl-CoA, both polypeptides were acylated to high levels, with the labeling again being decreased by 2-mercaptoethanol or NADPH. These results have demonstrated that acylation of the reductase represents an intermediate and rate-limiting step in fatty acid reduction. Moreover, the activated acyl groups are transferred in a reversible reaction between the synthetase and reductase proteins in the enzyme mechanism.  相似文献   

17.
We have employed a new pseudosubstrate, beta-(2-furyl)propionyl coenzyme A (FPCoA), to study the functional properties of two enzymes, fatty acyl-CoA dehydrogenase from porcine liver and fatty acyl-CoA oxidase from Candida tropicalis, involved in the oxidation of fatty acids. Previous studies from our laboratory have shown that the dehydrogenase exhibits oxidase activity at the rate of dissociation of the product charge-transfer complex. This raises the question of the difference in functionality between these two flavoproteins. To investigate these differences, we have compared the pH dependence of product formation, the isotope effects using tetradeuterio-FPCoA, and the spectral properties and chemical reactivity of the product charge-transfer complexes formed with the two enzymes. The pH dependencies of the reaction of FPCoA with electron-transfer flavoprotein (ETF) for the dehydrogenase and of the reaction of FPCoA with O2 for the oxidase are quite similar. Both reactions proceed more rapidly at basic pH values while substrate binds more tightly at acidic pH values. These data for both enzymes are consistent with a mechanism in which enzyme is involved in protonation of the carbonyl group of substrate followed by base-catalyzed removal of the C-2 proton from substrate. The C-2 anion of substrate may then serve as the active species in reduction of enzyme-bound flavin. The deuterium isotope effects for both enzyme systems are primary across the entire pH range, assuring that the chemically important step of substrate oxidation is rate limiting in these steady-state kinetic experiments. The two enzymes differ in the chemical reactivity of their product charge-transfer complexes.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

18.
19.
Summary Although abundant in most biological tissues and chemically well characterized, the fatty acid-binding protein (FABP) was until recently in search of a function. Because of its strong affinity for long chain fatty acids and its cytoplasmic origin, this protein was repeatedly claimed in the literature to be the transcytoplasmic fatty acid carrier. However, techniques to visualize and quantify the movements of molecules in the cytoplasm are still in their infancy. Consequently the carrier function of FABP remains somewhat speculative. However, FABP binds not only fatty acids but also their CoA and carnitine derivatives, two typical molecules of mitochondrial origin. Moreover, it has been demonstrated and confirmed that FABP is not exclusively cytoplasmic, but also mitochondrial. A function for FABP in the mitochondrial metabolism of fatty acids plus CoA and carnitine derivatives would therefore be anticpated. Using spin-labelling techniques, we present here evidence that FABP is a powerful regulator of acylcarnitine flux entering the mitochondrial -oxidative system. In this perspective FABP appears to be an active link between the cytoplasm and the mitochondria, regulating the energy made available to the cell. This active participation of FABP is shown to be the consequence of its gradient-like distribution in the cardiac cell, and also of the coexistence of multispecies of this protein produced by self-aggregation.  相似文献   

20.
Hydroxy fatty acids are widely used in chemical, food, and cosmetic industries as starting materials for the synthesis of polymers and as additives for the manufacture of lubricants, emulsifiers, and stabilizers. They have antibiotic, anti-inflammatory, and anticancer activities and therefore can be applied for medicinal uses. Microbial fatty acid-hydroxylation enzymes, including P450, lipoxygenase, hydratase, 12-hydroxylase, and diol synthase, synthesize regio-specific hydroxy fatty acids. In this article, microbial fatty acid-hydroxylation enzymes, with a focus on region-specificity and diversity, are summarized and the production of mono-, di-, and tri-hydroxy fatty acids is introduced. Finally, the production methods of regio-specific and diverse hydroxy fatty acids, such as gene screening, protein engineering, metabolic engineering, and combinatory biosynthesis, are suggested.  相似文献   

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