饲料中添加肉毒碱对黄颡鱼生长的影响

以鱼粉和豆粕为蛋白源、大豆油为脂质源配制成1个蛋白质水平（35％）X5个脂肪水平（4％，10％，16％，22％，26％）X2个肉毒碱水平（0mg／Kg,150mg／Kg）的10种配方饲料，投喂平均体重为（10．0±0．6）g的黄颡鱼，进行肉毒碱对黄颡鱼生长影响的研究。经100d饲养表明：饲养中添加150mg/Kg肉毒碱对黄颡鱼生长没有影响。在黄颡鱼低蛋白配合饲料中，体重增长率最大，饵料系数、蛋白质效率较好的是最低的脂肪含量组（4％）。高脂肪含量对黄颡鱼的生长不利。     

黄颡鱼饲料脂肪的最适含量

以鱼油/豆油(1∶1,W/W)为脂肪源,配制脂肪含量为5.21%、7.23%、9.27%、11.31%、13.33%、15.37%的半纯化饲料,投喂体重约8g的黄颡鱼40d,用于探讨饲料脂肪水平对黄颡鱼生长及饲料利用率的影响。试验结果表明当脂肪含量<11.31%时,鱼体的相对增重率、饲料转化率、蛋白质效率与脂肪含量呈正相关,当脂肪含量>11.31%时,鱼体的相对增重率、饲料转化率、蛋白质效率与脂肪含量呈负相关。肝体比和肌肉渗出损失随着脂肪添加量的增加而持续上升。脂肪水平对以上各项指标有显著性影响(P<0.05)。综合各项指标,可以确定黄颡鱼饲料脂肪的最适含量为11.31%。     

饲料蛋白质和能量水平对草鱼生长和鱼体组成的影响

采用3×3因子试验确定不同蛋白质和脂肪水平饲料对草鱼生长和鱼体组成的影响。初始平均体质量为0.75g的试验鱼放养在27个规格为85cm×35cm×95cm的网箱中,每箱放养50尾。日粮中的蛋白源、脂肪源和可消化碳水化合物源,分别采用鱼粉、豆油和糊精配制,日粮设3个粗蛋白水平,每个蛋白水平有3个能量水平饲养草鱼84d。结果表明MPLL组(粗蛋白为30%,粗脂肪为4%)的特殊生长率和蛋白质效率最高,饲料系数最低,但与LPML组(粗蛋白为25%,粗脂肪为6%)差异不显著;总的来看,脂肪含量在4%和6%时特定生长率和饲料系数以中蛋白质组(MP,30%)最高,脂肪含量在8%时特定生长率和饲料系数以低蛋白质组(LP,25%)最高,表明饲料脂肪水平对鱼的生长和饲料系数有显著影响。随着饲料可消化能的增加,鱼体的脂肪含量增加,而蛋白和灰分含量没有多大变化。综合饲料成本等因素,本试验初步确定草鱼幼鱼生长所需的最适蛋白水平为25%,DP/DE约为23.47mg·kJ-1。     

饲料蛋白能量比对草鱼幼鱼生长性能、蛋白利用和体成分的影响

以鱼粉和豆粕为蛋白源,鱼油和豆油等比例混合油为脂肪源,采用4×4因子实验来确定草鱼(Ctenopharyngodon idellus)幼鱼饲料中的合适蛋白能量比(P/E),其中饲料蛋白水平分别为20%、25%、30%、35%,能量水平为12.5、13.7、15、16.2 k J/g,饲料蛋白能量比的范围为12.1~27.3 mg/k J,共16组饲料,每组设3个重复,连续投喂初体质量(16.85±0.29)g的草鱼幼鱼10周,研究饲料蛋白能量比对草鱼幼鱼生长性能、蛋白利用和体成分的影响。结果表明:(1)最高末体质量和特定生长率出现在P/E为18.3 mg/k J组,而P/E为16.0 mg/k J组的饲料系数最高,蛋白质效率和蛋白沉积率最高组分别为P/E 12.10 mg/k J组和15.20 mg/k J组。(2)P/E为27.30 mg/k J组的能量沉积率和总氮排泄率最大。(3)在同一饲料蛋白水平下,鱼体的脂肪含量随饲料能量水平升高而升高;在同一饲料能量水平下,鱼体的蛋白含量随饲料蛋白含量升高而升高。对生长、蛋白利用、体成分的实验结果进行综合分析,草鱼幼鱼饲料的最适蛋白含量为30%,最适P/E为19.5 mg/k J。     

膨化饲料能蛋比对黄颡鱼幼鱼生长性能的影响

以黄颡鱼幼苗为研究对象,设计蛋白含量为36.5%、38%、39.5%、41%,能蛋比水平为8Kcal/g、8.5Kcal/g、9Kcal/g、9.5Kcal/g下的16种饲料,在恒温循环水养殖系统中养殖70天,研究不同能蛋比对黄颡鱼幼鱼生长性能的影响。结果表明:蛋白含量为39.5%,能蛋比为8.5Kcal/g的实验组,黄颡鱼生长性能最佳;蛋白含量低于38%,不能满足黄颡鱼营养需求,生长性能较差。蛋白含量为41%,能蛋比高于9Kcal/g后,不利于黄颡鱼幼鱼生长。因此,黄颡鱼幼鱼膨化饲料适宜的蛋白含量为38-41%,适宜的能蛋比为8-9Kcal/g,过高或过低的能蛋比均不利于黄颡鱼生长。     

克氏螯虾饲料中适宜的蛋白质含量和能量蛋白比研究

采用3×3因子试验法,设计了3种不同蛋白质水平(26%、29%、32%)及能最蛋白比水平(36、40、44 kl/g)的9种试验饲料,对体重(2.39±0.37)g的克氏螯虾(Procambarus clarkii)的适宜蛋白质含量及其蛋白能最比进行了研究,生长试验期42 d.结果表明,克氏螫虾幼虾配合饲料中适宜蛋白质含量为29.49%～32.24%,饲料的适宜能量蛋白比范嗣为34.67～37.46 kJ/g;当试验饲料蛋白质含量为31.86%,能量蛋白比为35.85 kJ/g时,试验虾获得最大增重率、最低的饲料系数、最高的蛋白质效率及最大的特定生长率.     

卵形鲳鲹幼鱼饲料中适宜蛋白能量比的研究

以鱼粉、豆粕为蛋白源,豆油、鱼油为脂肪源,配制9种不同蛋白能量水平的饲料,蛋白质3个水平(38%、43%、49%),每个蛋白水平设3个脂肪梯度(6%、10%、14%),其蛋白能量比为19.3～27.4mg/kJ。卵形鲳鲹初始质量为(25.02±0.16)g,每个处理设3个重复,每个网箱(1.5 m×1.0 m×2.0m)放养卵形鲳鲹苗20尾,养殖试验持续8周。结果显示,卵形鲳鲹特定生长率随饲料蛋白水平的升高而显著升高(P<0.05)。投喂含43%或49%蛋白质、6%脂肪饲料的卵形鲳鲹表现出较好的特定生长率。饲料中不同的脂肪水平未表现出蛋白质节约效应,较高的脂肪水平反而抑制了卵形鲳鲹的特定生长率、饲料效率和蛋白质效率。卵形鲳鲹鱼体蛋白和脂肪含量分别随饲料蛋白质和脂肪水平的上升而显著升高(P<0.05)。在该试验条件下,卵形鲳鲹幼鱼饲料中最适蛋白质、脂肪水平和蛋白能量比分别为43%、6%和24.4 mg/kJ。     

鱼粉和豆饼的比例对黄颡鱼生长的影响

以平均体重 11 3g的 385尾黄颡鱼为实验动物随机分为 7组 ,用 3种不同鱼粉和豆饼比例的饲料 ,进行6 4d饲养试验 ,结果表明 :饲料中蛋白质含量 38 4 6 %具有显著的增重效果 (P <0 0 1) ,蛋白质利用率 12 6 6 % ,鱼粉和豆饼的比例为 1∶0 5。     

饲料蛋白质和维生素C含量对黄颡鱼生长和免疫力的影响

将黄颡鱼种放养在网箱中,投喂蛋白质含量30.0%、38.0%或46.0%和维生素C磷酸酯0、500、1000或1500mg·kg-1的半纯饲料。50d的饲养表明:饲料蛋白质含量在38%～40%时,鱼的特殊生长率和蛋白质效率最高,饲料系数最低。饲料维生素C磷酸酯含量为847、850、994和634mg·kg-1时,血清总蛋白、γ球蛋白、溶菌酶活性最高,超氧化物歧化酶活力最低。饲料蛋白质含量从30%上升到38%时,鱼体蛋白含量由60.95%升到69.86%,脂肪由29.27%降至21.69%;达46%时,鱼体蛋白(64.35%)含量下降,而脂肪(26.06%)含量上升。饲料粗蛋白含量为38%时,鱼肌肉中饱和与单不饱和脂肪酸的含量分别极显著地低于和显著高于饲料粗蛋白为30%和46%组。后两组鱼肌肉n-3/n-6值极显著和显著高于饲料蛋白含量为38%时,两个高蛋白饲料组中,鱼肌肉中n-6系列多不饱和脂肪酸和亚麻酸含量极显著和显著高于饲料蛋白30%组。黄颡鱼种饲料中蛋白质和维生素C的最适含量分别为35.58%～40.60%和600～800mg·kg-1。     

饵料中不同维生素E添加量对黄颡鱼幼鱼生长和体色的影响

试验探讨了饵料中添加不同水平的维生素E对黄颡鱼生长及体色的影响,在基础饵料中分别添加0(对照组)、0.2、0.4、0.6、0.8和1.0 g/kg维生素E(含量50%)配制成1～6#饵料,在1～6#饵料中维生素E含量分别为68、175、268、364、482和562 mg/kg。在水温26～28℃下,用上述饵料分别投喂体重(21.18±13.31)g的黄颡鱼60 d,从相对增重率、饵料系数和成活率等方面来看,黄颡鱼饵料中维生素E适宜含量为268 mg/kg。     

对虾白斑综合征病毒蛋白质组的研究进展

白斑综合征病毒WSSV(White Spot Syndrome Virus,WSSV)是引起对虾大规模死亡的主要病毒性病原,且该病毒感染的宿主广泛。自WSSV基因组全序列公布以来,国内外的学者对WSSV的研究热点转移到该病毒基因产物功能的相关研究上面来。弄清WSSV感染机理是有效防治病毒的基础,而对其感染机理的阐释则主要是搞清病毒各蛋白在感染中的作用,这些是WSSV蛋白质组学的研究内容之一。分析WSSV蛋白同时可以在分子水平上为研究海洋和陆地生物病毒的进化趋势提供有力的基础。     

几种处理对三叶草叶蛋白提取率及蛋白质质量分数的影响

选用三叶草为试验材料,通过单因素试验设计,探讨料液比、加盐量、不同pH值和絮凝温度4个因素对三叶草叶蛋白提取率及蛋白质质量分数的影响。以叶蛋白提取率、蛋白质量分数为指标,以期获得三叶草叶蛋白提取基础参数。试验表明,料水比1:3、加盐量4%、pH值4.0、絮凝温度80℃时三叶草的叶蛋白提取率最高。     

Fast growth, protein turnover and costs of protein metabolism in yolk-sac larvae of the African catfish (Clarias gariepinus)

In fish larvae the costs of rapid growth may be accommodated by a decrease in the rate of protein turnover or by a reduction in the costs of protein synthesis. Protein growth, synthesis and degradation were measured in yolk-sac larvae of Clarias gariepinus and the costs of protein synthesis and protein growth were estimated. Growth rates were over 100% protein weight day^-1. Protein synthesis retention efficiency (retained protein per unit of synthesis) was estimated to be 69.6%, a value comparable to that of larger fish. The larvae used 43% of their oxygen consumption for protein synthesis. Nevertheless, protein synthesis costs were close to theoretical minima. Therefore, the high growth rates of catfish yolk-sac larvae seem to be possible through minimisation of the costs of protein synthesis. These low costs are associated with high rates of protein synthesis (138%protein weight day^-1), and elevated RNA concentrations (107 µg RNA mg^-1protein), which together suggest very high RNA efficiencies (12.9 g protein synthesized g^-1RNA day^-1).     

Effect of Dietary Protein Concentration on Growth and Processing Yield of Channel Catfish,Ictalurus punctatus Raised from Advanced Fingerlings to Large Marketable Size

Abstract

This study evaluated the effects of dietary protein concentration (26, 28, and 32%) and an all-plant protein diet (28% protein) on growth, feed efficiency, processing yield, and body composition of channel catfish, Ictalurus punctatus raised from advanced fingerlings to large marketable size (about 800 to 900 g/fish) for two growing seasons. Fingerling channel catfish (average weight = 56 g/fish) were stocked into twenty 0.04-ha ponds at a density of 18,525 fish/ha. Fish were fed once daily to satiation during the two growing seasons and fed according to recommended winter feeding schedules during the winter. There were no differences in diet consumption, weight gain, feed conversion ratio, survival, processing yields (carcass, shank fillet, and nugget), or fillet composition (moisture, protein, fat, and ash) among fish fed the various diets. These results indicate that a 26% protein diet containing plant and animal proteins or a 28% all-plant protein diet is adequate for channel catfish raised in ponds from advanced fingerlings to large marketable size without adversely affecting weight gain, feed efficiency, processing yield, or body composition. Large marketable-size channel catfish appear to use diets less efficiently but give higher processing yields compared to small marketable-size fish.     

Protein synthesis,growth and energetics in larval herring (Clupea harengus) at different feeding regimes

Rates of growth, protein synthesis and oxygen consumption were measured in herring larvae, Clupea harengus, in order to estimate the contribution that protein synthesis makes to oxygen consumption during rapid growth at 8°C. Protein synthesis rates were determined in larvae 9 to 17 d after hatching. Larvae were bathed in ³H phenylalanine for several hours and the free pool and protein-bound phenylalanine specific radioactivities were determined.Fractional rates of protein synthesis increased 5 to 11 fold with feeding after a period of fasting. Efficiencies of retention of synthesized protein were approximately 50% during rapid growth. Rapid growth in herring larvae thus appears to be characterized by moderate levels of protein turnover similar to those obtained for larger fish. Increases in growth rate occurred without changes in RNA concentration, i.e., the larvae increased the efficiency of RNA rapidly. Oxygen consumption rates were not correlated with growth rates. Protein synthesis was estimated to account for 79% of the oxygen consumption, and energy costs of protein synthesis were high, i.e., about 98 mmole O₂ g^–1 protein synthesized.     

Soybean protein concentrate as a protein source for turbot Scophthalmus maximus L.

In the first of two experiments, the effect of a gradual substitution of dietary fish meal with soybean protein concentrate (SPC) on growth, feed consumption and protein digestibility was examined in 13 g turbot Scophthalmus maximus. Five isonitrogenous and isoenergetic diets (50% protein and 22 kJ g^?1) containing SPC at protein replacement levels of 0, 25, 50, 75 and 100% were offered by hand twice daily. Growth rates of fish fed diets with zero and 25% replacement were not significantly different, with SGRs of 2.47 and 2.28, respectively. At higher replacement levels, growth rates decreased significantly with SGRs of 2.00, 1.33 and 0.68, respectively. Feed conversion ratios increased with soya replacement, with values of 0.68, 0.75, 0.89, 1.27 and 2.32, respectively, although there was no significant difference between the first two. Feed consumption rates remained constant up to 50% replacement, above which they decreased significantly, possibly because of reduced diet palatability. Apparent protein digestibility (APD) was not affected by the incorporation of SPC and ranged from 82.8 to 87.5%. Results suggest that protein catabolism increases in SPC‐rich diets, possibly because of rapid assimilation and utilization of the methionine supplement. In the second experiment, the importance of amino acid supplements and the beneficial effects of protecting these, either by coating them in protein or incorporating them in a protein–lipid emulsion, was investigated. Growth data provided some indication that the utilization of SPC may be improved by incorporating the methionine and lysine supplement in a protein–lipid emulsion prior to diet preparation, although this finding was not found to be statistically significant (0.1 < P < 0.2).     

饲料蛋白对翘嘴红鲌蛋白质周转代谢的影响

选择健康的翘嘴红(体重12.84±0.60g)为试验鱼,以红鱼粉为蛋白源,配制5个蛋白水平(31.04%、35.51%、40.89%4、6.62%、50.33%)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0、13.5%、27%、40.5%、54%的鱼粉蛋白,配制5个EAA关联度的等蛋白(40%)、等能(20MJ.kg-1)的半精制饲料,探讨饲料蛋白水平和大豆蛋白对鱼粉蛋白的替代对翘嘴红肌肉和肝胰脏蛋白质周转代谢的影响。8周饲养结果表明,饲料蛋白水平对翘嘴红的特定增重率(SGR)具有显著性影响(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);饲料蛋白水平对白肌、肝胰脏蛋白质生长率具有相似的影响,40.89%饲料蛋白组的白肌、肝胰脏蛋白质生长率分别达到2.13%.d-1,显著高于31.04%和35.51%两组(P<0.05),但与46.62%和50.33%饲料蛋白组无显著性差异(P>0.05)。饲料蛋白水平的增加促进了翘嘴红的生长和蛋白质的合成。肌肉蛋白质合成率(Ks)、蛋白质降解率(Kd)随饲料蛋白水平的增加而增加(P<0.05),肌肉蛋白质的增加归因于蛋白质合成的增加较降解的增加更占优势,蛋白质的沉积率在适宜蛋白水平时最高。当大豆蛋白分别替代13.5%2、7.0%4、0.5%的鱼粉蛋白时,翘嘴红的SGR与对照组差异不显著(P>0.05),而且都显著高于54.0%替代组(P<0.05)。白肌蛋白质生长率(Kg)也显著受到大豆蛋白替代的影响(P<0.01),当饲料中大豆蛋白对鱼粉蛋白替代量为40.5%时,与对照组相比,Kg极显著下降(P<0.01)。随着饲料中大豆蛋白对鱼粉蛋白替代量的增加,白肌Ks随之降低,当饲料中大豆蛋白对鱼粉蛋白替代量达54%时,与对照组相比,肌肉Ks显著下降(P<0.05)。白肌Kd与白肌Ks的变化趋势相似(P<0.1),而PDE没有受到饲料中大豆蛋白对鱼粉蛋白替代的影响(P>0.05)。可见随着大豆蛋白对鱼粉蛋白替代量的提高,氨基酸平衡关联度逐渐降低,蛋白质合成逐渐降低(P<0.05),生长下降,饲料必须氨基酸平衡程度的变化没有改变蛋白质的沉积效率。     

The interactive effects of dietary protein and energy on feed intake, growth and protein utilization of juvenile mulloway (Argyrosomus japonicus)

The objectives of this study were to describe the interactive effects of varying digestible protein (DP) and digestible energy (DE) contents on the feed intake, growth, protein utilization and whole body composition of juvenile mulloway ( Argyrosomus japonicus ) and to determine the optimal DP : DE ratio for growth. This was achieved by feeding mulloway diets containing one of four different DP levels (250–550 g kg⁻¹) at two DE levels (16 or 21 MJ kg⁻¹). Juvenile mulloway were stocked at each of two different sizes (70 or 200 g) in triplicate groups for each dietary treatment and fed twice daily to apparent satiation over 58 days. The results indicated that feed intake was not governed solely by energy demands but was also dependant on the DP content of the diet. Protein utilization did not improve with diets containing decreasing protein and increasing lipid content indicating that mulloway have a limited capacity to spare DP. Optimal DP content was found to be 444–491 g kg⁻¹ depending on the DE content of the diet and the size of mulloway and is within the range reported for other sciaenid species. The use of formulated diets with 28.6 g of DP MJ DE⁻¹ will achieve optimal growth and protein deposition for 70–275 g mulloway.     

Protein Hydrolysate Fractions from Sea Cucumber (Isostichopus badionotus) Inhibit Angiotensin-Converting Enzyme

Angiotensin-converting enzyme (ACE) inhibitory capacity was evaluated in hydrolysates from sea cucumber Isostichopus badionotus. The pepsin-pancreatin and Alcalase®-Flavorzyme® sequential systems were used. Hydrolysates were characterized in terms of degree of hydrolysis (DH), electrophoretic profile, and inhibitory activity. The Alcalase®-Flavorzyme® system produced hydrolysates with the highest DH, with that produced at 90 min exhibiting the highest ACE inhibitory action (86%). This hydrolysate was chosen for purification by ultrafiltration with five molecular weight cut-offs (< 1, 1–3, 3–5, 5–10, and > 10). The > 10-kDa fraction exhibited the highest ACE inhibitory action (80.7%) and was fractionated by gel fractionation chromatography. Of the 11 resulting fractions, IX had the highest ACE inhibitory action (73.4%) and lowest IC₅₀ value (2-μg prot/mL). Hydrolysis of sea cucumber I. badionotus with the Alcalase®-Flavorzyme® system produced hydrolysates with ACE inhibitory action. These contained a peptide with an IC₅₀ value comparable to those of synthetic ACE inhibitors.     

鱼排酶解物对鳙鱼鱼糜冻藏过程中蛋白质变性的影响

利用木瓜蛋白酶、低温碱性酶、风味蛋白酶酶解红鱼（Sciaerlops ocellatus）鱼排，分别获得木瓜蛋白酶酶解物（PPH）、低温碱性酶酶解物（LPH）和风味蛋白酶酶解物（FPH）。对3种酶解物化学成分及氨基酸组成进行分析，结果显示，3种酶解物中总氨基酸含量都在70％以上，总氮含量为82．12％～84．61％。酶解物分别以5％（质量比）量加入鳙鱼（Aristichthys nobilis）鱼糜中，冻藏于-20℃。测定冻藏过程中肌原纤维蛋白质盐溶性和Ca^2＋-ATPase活性的变化，同时测量鱼糜凝胶弹性的变化，并对冻藏样品进行扫描电镜观察，抗冻效果同商业抗冻剂（4％蔗糖、4％山梨醇、0．3％多聚磷酸盐混合剂）进行比较。结果表明，各酶解物能够在一定程度上抑制鱼糜蛋白质的冷冻变性，延缓肌原纤维蛋白质盐溶性和Ca^2＋-ATPase活性的下降，鱼糜凝胶质量下降减少，其中木瓜蛋白酶酶解物具有最好的效果。