草鱼对蛋白质和氨基酸离体消化率的比较分析

在离体条件下测定了草鱼肠道酶液对棉粕、红花粕、豆粕、菜籽饼、葵粕、菜粕、大豆、小麦麸、玉米等几种饲料蛋白质和氨基酸在0、1、3、5、7h时的离体消化率。结果表明:①草鱼对不同的饲料原料具有不同的蛋白质和氨基酸消化率,本试验中几种原料的粗蛋白消化率由高到低的顺序依次是大豆>豆粕>小麦麸>菜籽饼>葵粕>菜粕>棉粕1>玉米>红花粕>棉粕2;②在离体消化时,各种饲料保持了较高的消化率,氨基酸的消化率可以作为评价饲料蛋白质质量的指标;③从离体酶解反映过程分析,反应可以控制在5h内完成。     

草鱼肠道、肝胰脏对饲料蛋白质酶解速度的比较

草鱼样品体重(1543±213)g。采用离体消化培养和茚三酮比色方法,以草鱼前肠、中肠、后肠和肝胰脏的粗酶液作为酶源,对鱼粉、豆粕、菜粕和棉粕进行酶解,并测定酶解14h内,豆粕酶解液中氨基酸生成量随时间的变化,以及0至4h,内4种饲料蛋白质酶解液中氨基酸的生成量。结果表明,(1)在0至4h内,4种饲料酶解液OD570随时间变化的线性关系较好。(2)对于同种蛋白质饲料原料,以中肠组织粗酶液的酶解速度最大,其余依次为前肠、后肠及肝胰脏粗酶液。表明草鱼中肠对饲料蛋白质的酶解能力强于前肠和后肠,同时,肠道酶液的酶解速度均大于肝胰脏。(3)对于4种不同的蛋白质饲料原料,以鱼粉酶解氨基酸生成速度最大,其他依次为豆粕、菜粕、棉粕。(4)草鱼肝胰脏粗酶液对豆粕的酶解氨基酸生成速度最大,表明草鱼对豆粕进行酶解消化的能力较强。实验证实,饲料原料种类的差异和饲料蛋白质组成与性质的差异使其酶解氨基酸生成量和生成速度有差异。     

草鱼肠道对10种必需氨基酸的跨壁运输量

采用离体灌注实验系统和茚三酮对氨基酸显色的实验方法，对跨过草鱼肠道壁的氨基酸进行定量分析，在相同的实验环境下，分别研究草鱼肠道对lO种必需氨基酸的吸收转运量。结果表明，在60min内草鱼肠道可对灌流的氨基酸进行持续的吸收转运，并在肠道外积累；当肠道内灌流氨基酸浓度逐渐增加时，肠道外只有苏氨酸的浓度与其起始浓度呈正相关变化，其他9种氨基酸在高浓度(10．0mmol／L)时的吸收转运量均显著下降，表现出高浓度氨基酸对吸收转运的“抑制”效应；通过对吸收转运量达到最大值时实验氨基酸的浓度与吸收转运量的比较，以及在氨基酸吸收转运量随时间的变化规律等的比较分析表明，l0种氨基酸在肠道吸收、转运量的变化行为特征有一些共性，也有氨基酸种类特异性。总体表现为，草鱼肠道对苏氨酸、异亮氨酸和亮氨酸等具有很高的吸收转运能力。而对精氨酸、苯丙氨酸、组氨酸等的吸收、转运能力较差。     

草鱼对27种饲料原料中氨基酸的表观消化率

本试验以0.5％Cr2O3为指示物,按照“70％基础饲料 30％试验原料“的饲料配制方法,在可控条件的室内循环养殖系统中用2龄草鱼种（体重150-200g）对常用的饲料原料的氨基酸表观消化率进行测定。试验选用了进口鱼粉、国产鱼粉、蟹粉、肉粉、肠衣粉、酵母、菜饼、黄菜粕、菜粕、双低菜籽粕、豆粕、膨化大豆、芝麻饼、棉粕、玉米胚芽粕、玉米蛋白粉和酒糟粉共17种商品蛋白质饲料原料,玉米、麦麸、次粉、米糠、标粉、小麦、大麦、玉米糟、稻谷、药渣共10种能量饲料原料,得到了每种原料的16种氨基酸的表观消化率。表观消化率主要规律表现为：草鱼对原料蛋白质消化率高时对氨基酸的总消化率也高,如对鱼粉、豆粕的消化率高;对玉米类原料如玉米蛋白粉、玉米渣、玉米的氨基酸消化率较低,而对小麦类原料如小麦粉、麦麸、次粉等的消化率相对较高;在植物饼粕类中,草鱼对豆粕和菜粕的消化率较高,而对棉粕的消化率则相对较低;对同种原料的16种不同的氨基酸的表观消化率也有很大的差异,这种差异的规律性较差。     

草鱼和鲤鱼对以花生壳为主的饲料的消化试验

<正> 因地制宜地扩大养殖鱼类的饲料来源,对发展淡水鱼类养殖有重要意义。近年来不少地区因地制宜地利用稻草、芝麻杆、黄豆杆、玉米杆等农副产品加工后养鱼都取得了一定效果,我省滇南建水,蒙自一带、盛产花生,每年均有大量花生外壳当作废物处理。根据已有的分析,花生外壳具有鱼类     

鲤,草鱼对营养物质消化吸收的研究现状

本文综述了七十年代以来国内外报道的有关鲤、草鱼消化道结构、消化酶特性和物质代谢等与消化吸收之间的关系,为合理配制饲料和科学投饲提供了理论依据。     

饲料蛋白质和能量水平对草鱼幼鱼生长和消化酶活性的影响

在水温24～29℃下,将675尾规格整齐、健康、体质量为（35.59士0.44）g的草鱼（Ctenopharyngodon idel-lus）随机分为9个处理,每处理3个重复,放养于水泥池中的网箱（100cm×50cm×100cm）内,投喂以鱼粉和豆粕为蛋白源,豆油作为脂肪源配制的3个蛋白水平（24%、28%、32%）,每一蛋白水平设3个脂肪水平（4%、6%、8%）,共计9种饲料。饲料蛋能比（P/E）在15.81-22.46 mg·kJ-1之间。92d的饲养表明：D4组（蛋白质含量为28.02%,脂肪为4.30%）草鱼的特定生长率最高,显著高于其他各组（P〈0.05）。随着饲料中蛋白含量的增加,草鱼全肠中蛋白酶的活力逐渐升高,之后又降低,以D4组饲料的蛋白酶活性最高,显著高于D1、D8和D9（P〈0.05）。本实验表明,该生长阶段的草鱼所需最适蛋白水平为28.02%,能量为14307kJ.kg-1,P/E约为19.58mg·kJ-1。     

实用饲料补充结晶或包膜赖氨酸对草鱼生长、血清游离氨基酸和肌肉蛋白质合成率的影响

研究设计 4种试验饲料 (纯化饲料、实用饲料以及分别补充结晶和包膜赖氨酸的两种实用饲料 )。试验草鱼放养在玻璃钢水族箱 (10 0cm× 5 0cm× 5 0cm)中 ,每箱放养 30尾 (平均体重 7.2 7± 0 .5g) ,每种处理设 3个平行组 ,饲养 9周。试验结果表明 ,纯化饲料组的增重率和蛋白质合成率 (Ks)明显高于 3组实用饲料 (P <0 .0 5 )。实用饲料补充包膜赖氨酸与不补充或补充结晶赖氨酸比较 ,增重率、蛋白质效率、血清必需氨基酸平衡指数(EAAP)和蛋白质合成率都得到改善。包膜赖氨酸 ,是补充饲料蛋白质的一种很好的途径。     

中国对虾对16种饲料的蛋白质和氨基酸的消化率

本文利用三氧化二铬为指示物，测定了平均体长在８．０－９．０厘米的对虾对卤虫等１６种不同饲料源的蛋白质和氨基酸的消化率。按消化率的高低顺序排列则为：卤虫，蓝蛤，熟豆饼、秘鲁鱼粉、生豆饼、ＦＳ酵母、花生饼、ＥＳＢ酵母、棉籽饼、肉粉、菜籽饼、羽毛粉、ＴＰＬ－３２酵母，血粉、麦麸和玉米粉，该研究结果为评价某一饲料源的营养价值和开发适于中国对虾的人工配合饲料提供了依据。     

草鱼对六种青饲料的消化与利用研究

本文就六种陆生植物饲料(一年生黑麦草、多年生黑麦草、燕麦、红三叶、苦荬菜和聚合草)的营养成分及草鱼对它们的消化率和利用率,草鱼的生长及鱼肉的品质进行了比较研究。一年生黑麦草,多年生黑麦草和苦荬菜为草鱼适口的饲料,其蛋白质消耗分别为77.45％、76.79％和78.20％,饲料系数分别为28.69、32.81和26.30。鱼肉中粗蛋白质的含量也以食一年生黑麦草(83.40％)、多年生黑麦草(88.07％)者为最高,食聚合草者最低(75.92％)     

草鱼肠道芽孢杆菌的鉴定及产酶能力分析

从100 g左右的健康草鱼(Ctenopharyngodon idellus)肠道中分离出3株疑似芽孢杆菌(Bacillus)菌株(G1、G2、G3),并通过对其进行生理生化特征、16S rDNA全序列和产酶能力的分析,筛选出1株高产酶能力的益生菌株。结果显示:G1、G2和G3菌株与枯草芽孢杆菌在16S rDNA序列相似性≥99%的水平上聚为同一分支,结合形态观察和生理生化特征,最终鉴定G1、G2和G3菌株均为枯草芽孢杆菌(Bacillus subtilis);以水解圈直径/菌落直径比值评定了G1、G2和G3菌株的产纤维素酶、淀粉酶和蛋白酶的能力,其中G1菌株产纤维素酶、淀粉酶和蛋白酶能力(比值分别为2.9、2.2和3.3)均高于G2、G3菌株,具有作为益生菌的潜力。     

The attractive effects of amino acids and some classical substances on grass carp (Ctenopharyngodon idellus)

Fish Physiology and Biochemistry - Grass carp (Ctenopharyngodon idellus) is one of the most essential fishing species in China. The bait for this fish is rapidly developing. However, the study on...     

基因重组草鱼生长激素(r-gGH)对草鱼鱼种生长的促进作用

家蚕多角体病毒表达系统在家蚕体内表达基因重组的草鱼生长激素(r-gGH),具有与天然草鱼生长激素(GH)相似的免疫原性和生物活性。为了节省基因工程研究中的下游工作 (基因产物的分离和提纯),本研究将含有r-gGH的家蚕直接作为饵料源,冻干并磨碎后拌在饵料中投喂草鱼鱼种,通过养殖实验及生化测定分析对比r-gGH促进草鱼鱼种生长的剂量依存关系,筛选活性强的处理剂量和处理时间,期望为鱼类养殖生产提供一种较为经济、来源容易、方法简易而又切实可行的促进鱼种生长并且可以大规模应用的方式。实验结果表明,投喂含有r-gGH的家蚕,有相当一部分被鱼体消化道吸收,进入血液循环。投喂2 h和6 h 后,草鱼鱼种的血清GH水平均显著高于对照组(投喂基本饲料)和投喂正常家蚕组;每天投喂和隔2天投喂,均使草鱼鱼种的血清GH水平显著升高,并对草鱼鱼种生长都有明显的促进作用。短期(3 d)和长期(42 d)投喂含有r-gGH 的家蚕,无论是低剂量(10 mg·g^-1饲料)还是高剂量(20 mg·g^-1饲料),均极其显著地提高草鱼鱼种的血清GH水平;长期(42 d)投喂亦对草鱼鱼种的生长有显著的促进作用,鱼体的相对体重增长率、相对体长增长率、食物转化率和肥满度显著增加。     

In vitro exposure to copper influences lipid metabolism in hepatocytes from grass carp (Ctenopharyngodon idellus)

In the present study, three different copper (Cu) concentrations (control, 10 and 100 μM, respectively) and three incubation times (24, 48 and 96 h) were chosen to assess in vitro effect of Cu on lipid metabolism in hepatocytes of grass carp Ctenopharyngodon idellus. Increased glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and carnitine palmitoyltransferase I activities were observed in hepatocytes with increasing Cu concentration and exposure duration. Cu decreased mRNA levels of several lipogenic and lipolytic genes at 24 h. However, at 48 h, Cu down-regulated the process of lipogenesis but up-regulated that of lipolysis. The Cu-driven up-regulation of lipolytic genes was maintained after 96 h and accompanied by a decreased intracellular triglyceride accumulation, while no effect on lipogenic genes was shown. Thus, 96-h Cu exposure induced lipid depletion, possibly due to the up-regulation of lipolysis. Although in this process, lipogenesis might be up-regulated, it was not enough to compensate lipid consumption. Our study represents the first approach to concentration- and time-dependent in vitro effects of Cu on lipid metabolism of fish hepatocytes and provides new insights into Cu toxicity in fish at both enzymatic and molecular levels.     

草鱼鱼种对胆碱需要量的研究

用不含胆碱的饲料饲养草鱼鱼种，草鱼鱼种生长减慢，饲料效率降低，肝脏脂肪浸润，血浆总脂，甘油三脂，胆固醇和磷脂含量降低，随着饲料中胆碱含量的添加，草鱼生长和饲料效率改善，肝脏脂肪含量降低，血浆总脂、甘油三脂、胆固醇，磷脂含量回升。当饲料中胆碱添加量达到０．３％以上时，草鱼生长率最高，肝脏脂肪含量，血浆总脂、甘油三脂，胆固醇，磷脂与摄食天然饲料（浮萍）的草鱼基本相同。在本研究条件下，建议草鱼鱼种饲料中     

Bacterial communities in Chinese grass carp (Ctenopharyngodon idellus) farming ponds

Bacterial communities in the water column and sediment of 12 commercial grass carp (Ctenopharyngodon idellus) farming ponds were analysed. At the same time, physical and chemical environmental parameters were measured, including secchi depth (SD), total nitrogen (TN), total phosphorus (TP) and chemical oxygen demand (COD_Mn). From 12 water samples and 12 sediment samples, 39 different ribotypes were detected with PCR‐denaturing gradient gel electrophoresis (PCR‐DGGE). The ribotype richness showed that bacterial species in the water column differed among these ponds, and the result of sequencing further revealed the dominant and common bacterial species. In total, 32 bacterial species belonging to seven phyla (Proteobacteria, Bacteroidetes, Actinobacteria, Cyanobacteria, Acidobacteria, Fibrobacteres and Fusobacteria) were identified. Ordination via canonical correspondence analysis (CCA) on the DGGE data and environmental parameters indicated that the composition of bacterial community was significantly influenced by SD.     

Quantifying the dietary potassium requirement of subadult grass carp (Ctenopharyngodon idellus)

A growth trial lasting for 12 weeks was conducted in 21 net cages to determine the dietary potassium (K) requirement of subadult grass carp (Ctenopharyngodon idellus) (Average weight: 331.3 g). Seven isonitrogenous and isoenergetic semi‐purified diets were compounded with different dietary K level. The specific growth rate (SGR) of fish was significantly (P < 0.05) improved by dietary K supplementation, SGR and the gill Na⁺‐K⁺ ATPase activity increased first and then decreased (P < 0.05) as dietary K level increased. The highest SGR and gill Na⁺‐K⁺ ATPase activity values were both observed at 6.38 g kg^?1 group. Dietary K level showed significant (P < 0.05) effect on serum superoxide dismutase (SOD) and glucose (GLU), the maximum values of SOD and GLU were in 8.42 and 6.38 g kg^?1 group, respectively. The body lipid content of the 6.38 g kg^?1 group was significantly (P < 0.05) lower than that of the control. However, the ash content in the 8.42 g kg^?1 group was significantly higher than those in the 1.21, 2.21, 4.41 and 6.38 g kg^?1 group. When dietary protein was 320 g kg^?1 and the waterborne potassium ranged from 6.86 to 9.10 mg L^?1, the dietary K requirement for subadult grass carp judged from SGR and gill Na⁺‐K⁺ ATPase activity is 5.38 and 7.41 g kg^?1 diet, respectively.     

A review of intestinal microbes in grass carp Ctenopharyngodon idellus (Valenciennes)

Grass carp, Ctenopharyngodon idellus, harbours complex intestinal bacterial communities, which are important in several physiological processes of their host. Intestinal microbiota of grass carp have been previously described in numerous studies. However, an overview on the bacterial community diversity, including their establishment, their functions in host's nutritional processes and immune‐related responses, and use as probiotics, is absent. This study aimed to summarize the current understanding of the grass carp intestinal microbiota. In this review, we provide general information on the establishment and composition of intestinal microbial communities and factors influencing the diversity of gut microbiota. Also, this review covers the dietary effects of probiotics, prebiotics and/or synbiotics on the grass carp intestinal microbial communities and physiological characteristics. Although our knowledge of the grass carp intestinal microbiota is expanding rapidly, further studies on the factors affecting the diversity of intestinal microbes, interactions between intestinal microbiota and their hosts and application of probiotics/prebiotics/synbiotics in aquaculture industry, are needed.