翘嘴红鲌对饲料蛋白的营养需求及豆粕对鱼粉的适宜替代量

选择健康的翘嘴红(Erythroculter ilishaeformisBleeker)为实验鱼,体质量(12.84±0.60)g。实验分为两部分进行。实验Ⅰ以褐鱼粉为蛋白源,配制5个蛋白水平(31.04%、35.51%、40.89%、46.62%、50.33%)的等能、等必需氨基酸(EAA)平衡关联度的半精制饲料,探讨翘嘴红对饲料蛋白的需求;经过8周饲养,实验Ⅰ的结果表明,饲料蛋白含量对翘嘴红的增重率、饲料效率和蛋白效率具有显著影响。方差分析表明,40.89%饲料蛋白组的鱼体增重率显著高于31.04%、35.51%饲料蛋白组(P<0.05),但是与46.62%和50.33%饲料蛋白组没有显著性差异(P>0.05);31.04%3、5.51%和40.89%饲料蛋白组的蛋白效率显著高于46.62%和50.33%饲料蛋白组(P<0.05);40.89%、46.62%和50.33%饲料蛋白组的饲料效率显著高于31.04%和35.51%饲料蛋白组(P<0.05)。依据折线模型分析翘嘴红的增重率、二次多项式回归分析蛋白质效率,适宜饲料蛋白水平为37.43%~41.15%。实验Ⅱ以豆粕替代鱼粉,大豆蛋白分别替代0.0%、13.5%、27%、40.5%和54%的鱼粉蛋白,配制5个EAA关联度的等蛋白(40%)、等能(20 MJ.kg-1)的半精制饲料,探讨翘嘴红饲料中大豆蛋白对鱼粉蛋白的适宜替代量。结果表明,当大豆蛋白分别替代13.5%2、7.0%和40.5%的鱼粉蛋白时,翘嘴红的增重率和蛋白效率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),因此,本实验条件下,大豆蛋白对鱼粉蛋白的最大替代量为40.5%,饲料动、植物蛋白适宜比为3∶2。     

豆粕替代鱼粉对青鱼幼鱼生长及生理生化指标的影响

以初始体重(5.90±0.01)g的青鱼(Mylopharyngodon piceus)为研究对象,用豆粕替代不同水平鱼粉,配制5种等氮等能的实验饲料,分别为30%鱼粉(对照组)、25%鱼粉、20%鱼粉、15%鱼粉和15%鱼粉+晶体氨基酸,试验持续8周。结果显示:当鱼粉含量为15%时,其增重率、特定生长率、肌肉鲜味氨基酸含量和总氨基酸含量显著低于对照组,而饲料系数则显著高于对照组,添加晶体氨基酸对青鱼生长无显著改善;各处理组间甘油三酯(TG)、总蛋白(TP)、总胆固醇(TC)含量及谷丙转氨酶(ALT)活性无显著差异,但15%鱼粉组和15%鱼粉+晶体氨基酸组的青鱼的血糖含量和谷丙转氨酶活性显著高于对照组。结果表明,青鱼幼鱼实用饲料中鱼粉含量以不低于20%为宜,添加晶体氨基酸对青鱼幼鱼的生长无改善作用。     

饲料中添加维生素C对翘嘴鲌鱼种生长及组织中抗坏血酸含量的影响

在翘嘴(Culter alburnus)鱼种基础饲料中添加相当于抗坏血酸含量为0 mg/kg、25 mg/kg、50 mg/kg、100 mg/kg、150 mg/kg、200 mg/kg和400 mg/kg的包膜维生素C(Vc),制成7种实验饲料,饲养初始体质量为(3.71±0.11)g的7组翘嘴鱼种8周,每个实验组包含3个重复。结果表明,摄食不添加Vc饲料的实验鱼成活率显著低于其他Vc添加组(P<0.05)。饲料中Vc添加量为0~50 mg/kg时,对鱼体增重有显著影响(P<0.05),鱼体增重随添加量的增加而上升。但添加量继续增大,对鱼体增重不再有显著影响(P>0.05)。饲料中维生素C添加量为0和25 mg/kg时,饲料效率和蛋白质效率低于其他各组(P<0.05)。试验饲料中Vc不同添加量对肝体指数和全鱼体成分无显著影响(P>0.05)。肌肉中抗坏血酸含量随饲料中Vc添加量加大而不断上升,二者呈正相关关系(P<0.05)。肝胰脏抗坏血酸含量在Vc添加量≤100 mg/kg时,随饲料中Vc添加量加大而不断上升(P<0.05),但高于此添加量时,则肝胰脏中抗坏血酸不再随添加量的上升而有显著变化(P>0.05)。分别以鱼体增质量和肝胰脏中抗坏血酸为指标,经折线模型(Brokenline model)回归分析求得翘嘴鱼种饲料中Vc的适宜添加量分别为53 mg/kg和97 mg/kg。[中国水产科学,2007,14(1):106-112]     

饲料中豆粕替代鱼粉比例对牙鲆生长性能及生化指标的影响

以鱼粉和豆粕分别为主要动物性和植物性蛋白源,研究饲料中不同豆粕替代鱼粉比例对牙鲆幼鱼生长性能和生化指标的影响。设计4∶1、3∶1、2∶1和1∶1四种不同动植物蛋白比的等氮等脂饲料配方,按配方制备试验饲料,分别表示为D1、D2、D3和D4。牙鲆幼鱼随机分配到12个设有循环水系统的玻璃钢桶内(900L),每3桶鱼饲喂一种饲料,每天投喂饲料2次,每次达到表观饱食,饲喂期为56d。以增重率(WGR)、饵料系数(FCR)、特定生长率(SGR)、蛋白质效率(PER)、肝体指数(HSI)、肥满度(CF)、鱼体成分和饲料成本为依据,综合评价饲料中不同比例的豆粕替代鱼粉比例对牙鲆的饲养效果。通过测定尿素氮(BUN)、谷丙转氨酶(GPT)、谷草转氨酶(GOT)、游离脂肪酸(FFA)、总蛋白(TP)、甘油三酯(TG)、胆固醇(CHO)、高密度脂蛋白胆固醇(HDL-C)及低密度脂蛋白胆固醇(LDL-C)等生化指标,研究饲料中不同豆粕替代鱼粉比例对牙鲆蛋白质代谢和脂肪代谢的影响。随豆粕比例的增加,WGR、PER和SGR逐渐降低,FCR逐渐增加,当饲料中豆粕比例在24%以上时差异显著(P<0.05);HSI逐渐增加,且D1组显著低于其他...     

饲料不同蛋白水平对翘嘴鲌生长性能的影响

为了解翘嘴鲌对饲料中蛋白质的需求量,根据翘嘴鲌的体成分拟定饲料配方,设计了不同蛋白水平(蛋白质含量分别为34.46 %、37.20 %、38.82 %、41.5 %、43.58 %)的5种饲料,用以进行饲养试验,分别饲喂体质量相近(约1.2 g)的翘嘴鲌幼鱼。60 d后,测定每组幼鱼的生长性能(全长、体长、湿重、肌肉水分、粗蛋白及粗脂肪含量)。试验结果表明,翘嘴鲌的体长、全长、湿重随饲料蛋白水平的高低变化规律明显,蛋白水平为38.82 %的试验组,鱼的生长性能最佳。经回归分析得出的初步结论,并结合翘嘴鲌的生长和体蛋白积累情况,认为翘嘴鲌幼鱼饲料的适宜蛋白水平为39 %～40 %。     

不同饲料对翘嘴红鲌繁育的影响

2004年6月分别用活鱼、颗粒饲料与活鱼、颗粒饲料等3种不同饲料培育3足龄的翘嘴红鲌,对其性腺发育、人工繁殖及鱼苗活力进行了研究。结果表明,不同饲料培育的亲鱼,其相对怀卵量、卵巢系数、卵径无显著差异;而卵的重量,长期投喂活鱼的明显重于投喂颗粒饲料的。亲鱼的催产率和受精率不受饲料的影响,但孵化率和鱼苗活力(体质),长期投喂活鱼的好于投喂颗粒饲料的。     

豆粕替代鱼粉对鲤鱼生长的影响

以鱼粉和豆粕作为蛋白源。以植物蛋白分别替代0.14％,28％,42％,56％,71％,86％和100％的动物蛋白设计出等蛋白（30％左右）等能（15．77kJ／g左右）的8种不同动植物蛋白比饲料。通过65d的养殖,结果表明：鲤鱼的特定生长率在豆粕替代鱼粉比例71％时为0．82％／d,除与豆粕替代比例为0时的试验组无显著差异外（P〉0．05）,显著大于其余各试验组（P〈0．05）;蛋白效率在豆粕替代鱼粉比例86％时最大,分别为1.29％,除与豆粕替代比例71％时差异不显著外（P〉0．05）,与其余试验组差异显著（P〈0．05）;饵料系数在豆粕替代鱼粉比例86％时最小为2．42,与豆粕替代比例71％时差异不显著外（P〉0．05）,但与试验组差异显著（P〈0．05）。则本试验中动植物蛋白比为0．37：1-0．18：1时,鲤鱼的生长能达到较好的效果。     

低鱼粉饲料中添加牛磺酸对黄鳝生长、消化率及肠道酶活性的影响

该研究对体质量为(25.03±0.02) g的健康黄鳝(Monopterus albus)进行了10周的养殖实验,探究了低鱼粉饲料中添加牛磺酸对黄鳝生长、消化率及肠道酶活性的影响。实验设置了高鱼粉组(42%, FM)、低鱼粉组(22%,T_0)以及在低鱼粉饲料中分别添加0.2%(T_(0.2))和0.5%(T_(0.5))牛磺酸的4个处理组,每组5个重复。结果显示,与FM组相比,T_0组黄鳝的增重率、蛋白质效率、干物质消化率和蛋白质消化率显著下降(P0.05),饲料系数显著上升(P0.05)。添加适量牛磺酸可显著提高黄鳝的增重率、蛋白质效率和干物质消化率,降低饲料系数(P0.05),但T_(0.5)组黄鳝的增重率、蛋白质效率和饲料系数与T_0组相比无显著性差异(P0.05)。此外,T_0组肠道肌酸激酶(CK)、钠钾ATP酶(Na~+-K~+-ATPase)、碱性磷酸酶(AKP)、胰蛋白酶(TRYP)和脂肪酶活性显著低于FM组(P0.05),T_(0.2)组的上述肠道酶活性均显著升高(P0.05),T_(0.5)组肠道Na~+-K~+-ATPase、AKP、TRYP和脂肪酶(LPS)活性虽高于T_0组,但无显著性差异(P0.05)。综上,低鱼粉饲料中添加0.2%牛磺酸可提高黄鳝的生长,改善肠道消化吸收功能,但添加过量牛磺酸(0.5%)效果不明显。     

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。     

饲料蛋白对翘嘴红鲌蛋白质周转代谢的影响

在养殖虾夷扇贝（Patinopecten yessoensis）的生产过程中需要多次将其按大小分级。传统方法采用筛子和分级机筛分，会使扇贝受到振动、碰撞。振动影响扇贝生长发育，碰撞使扇贝边缘受到损伤，贝壳碎裂外套膜裸露在壳外，造成病贝、死贝，且机械筛分分级精度低，人工筛分劳动强度大、效率低。本文研究一种新的方法，利用机器视觉检测扇贝大小。通过摄像头获取扇贝图像、计算机对输入的图像进行预处理、图像分割、膨胀腐蚀，提取扇贝的面积等特征值，建立扇贝的几何模型、数学模型，确定面积与壳长的关系，进一步识别扇贝的大小。试验表明，该方法检测速度快，正确率高，能够满足虾夷扇贝分级要求。摄像头与扇贝不接触，可以避免机械振动、碰撞对扇贝的损伤。     

Effects of dietary protein and lipid levels on growth,body composition and flesh quality of juvenile topmouth culter,Culter alburnus Basilewsky

Nine experimental diets at three protein (35%, 40% and 45% crude protein) and lipid (5%, 8% and 11% crude lipid) levels with variable digestible protein to digestible energy (DP/DE) ratios ranged from 21.9 to 27.8 g protein MJ^?1 were fed to topmouth culter (Culter alburnus Basilewsky) fingerlings (initial weight 6.5 ± 0.9 g) in triplicated groups (30 fish per replicated) for a period of 10 week to assess the optimum dietary DP/DE ratio and the protein sparing effect by utilizing dietary lipid. 27 cages of 1.5 m³ capacity placed in a lake located in Wuhan were used for rearing the fish. At the end of the experiment, maximum weight gain and thermal‐unit growth coefficient was found in fish fed diet D4 with 45% protein, 8% lipid and P/E ratio of 26.2 g protein MJ^?1, but without a significant difference compared to fish fed diet D5 with 40% protein, 8% lipid and DP/DE ratio of 25.3 g protein MJ^?1. The best flesh quality evaluated by muscle collagen content was found in fish fed D5. High fat accumulation with increasing dietary lipid levels was observed in whole body but not in muscle tissue. Hence, it may be concluded that the optimum formulation for maximum growth and quality of topmouth culter is a diet containing 40% protein and 8% lipid with a resultant DP/DE ratio of 25.3 g protein MJ^?1. In addition, the protein sparing effect by inclusion lipid was observed but limited.     

Effect of soybean meal replacement by cottonseed meal on growth,feed utilization and some blood physiological/biochemical indices of juvenile black carp,Mylopharyngodon piceus

A feeding trial was conducted to evaluate the effect of replacing soybean meal (SBM) with cottonseed meal (CSM) for juvenile black carp. The inclusion levels of CSM were 0 (control), 96.6, 193.3, 289.8 and 386.5 g kg^?1, in which 0, 25, 50, 75 and 100% of protein from SBM were replaced with that from CSM respectively. The results showed that up to 75% of SBM could be replaced by CSM without significant reduction in growth. The apparent digestibility coefficients of dry matter and protein, red blood cell and white blood cell count were significantly decreased with the increase in dietary CSM levels (P < 0.05). The activities of serum catalase (CAT), lysozyme (LSZ) and complement C3 were significantly lower than that of control group when dietary CSM level were increased to 386.5 g kg^?1, 96.6 g kg^?1 and 289.8 g kg^?1 or higher respectively. The alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in serum were significantly higher than that of control group when dietary CSM levels were increased to 289.8 g kg^?1 or higher (P < 0.05). These results suggested that growth of black carp was not affected when CSM levels up to 289.8 g kg^?1; however, negative influence on immune and liver function was found when CSM levels up to 96.6 g kg^?1 and 289.8 g kg^?1 respectively.     

Effect of dietary replacement of fish meal by soybean protein concentrate on growth performance and phosphorus discharging of juvenile black sea bream,Acanthopagrus schlegelii

The 8‐week experiment was conducted to evaluate the effects of partial replacement of fish meal (FM) with soybean protein concentrate (SPC) on juvenile black sea bream, Acanthopagrus schlegelii (10.70 ± 0.04 g). Diets were formulated to replace FM protein by SPC at 0, 8, 16, 24, 32 or 40% (designated as T1, T2, T3, T4, T5 and T6, respectively). Diets except T1 were supplemented with phytase at 2000 phytase activity U kg^?1. The results showed that survival rate, growth performance and feed utilization were not significantly affected by increasing dietary SPC. Fish fed diet T3 had higher feed intake compared to those fed T1, T2 and T5 diets. Whole body compositions of black sea bream were significantly influenced by SPC replacing FM except for protein, ash and phosphorus content. Condition factor of fish was significantly lower in T2 than that of fish in T3 group. Apparent digestibility coefficients (ADCs) of dry matter was higher in fish fed T6 diet than those of fish fed T1 and T2 diets, ADCs of phosphorus increased with dietary SPC level up to T3 and then decreased. The results obtained in this study indicate that FM protein could be effectively replaced by SPC protein with phytase in diet of black sea bream.     

饲料中豆粕蛋白替代鱼粉蛋白对齐口裂腹鱼幼鱼生长性能、体成分及血液生化指标的影响

试验分别以豆粕替代0(对照组)、20%、40%、60%、80%、100%的鱼粉蛋白设计出6种等氮等能的饲料配方, 按照配方配制试验饲料(A1、A2、A3、A4、A5和A6)。将540尾体质量为(14.67±0.51) g的齐口裂腹鱼随机分为6个试验组, 每组3个重复, 每个重复30尾试验鱼, 分别投喂6种不同的试验饲料, 养殖时间为45 d。结果表明, 豆粕蛋白替代水平对齐口裂腹鱼的生长有显著影响。豆粕替代鱼粉蛋白的比例为60%时, 试验鱼的增重率(WGR)、特定生长率(SGR)、饲料蛋白效率(PER)均达到最高(分别为118.08%、1.95%/d和207.22%), 饵料系数(FCR)最小(1.27)(P<0.05)。与其余各试验组相比, 替代比例为100%的试验组的WGR、SGR、PER显著降低, FCR显著升高(P<0.05)。通过二次多项式回归分析可知, 齐口裂腹鱼生长性能最佳时豆粕蛋白替代比例为34.25%~45.46%; 随着豆粕替代鱼粉蛋白比例的增大, 鱼体水分、粗灰分、肥满度差异不显著(P>0.05), 粗蛋白在豆粕蛋白替代水平为60%时达到最高(15.53%), 但在豆粕蛋白替代比例小于80%时试验鱼体粗蛋白、粗脂肪含量无显著差异(P>0.05), 肝体指数则随豆粕蛋白替代水平增加而增大, 但在0~80%之间均无显著差异(P>0.05)。随着豆粕蛋白替代比例的增加, 超氧化歧化酶(SOD)的活性有一定的波动, 在豆粕蛋白替代比例为40%达到最高, 豆粕蛋白替代比例在20%~60%时, 溶菌酶(LSZ)的活性逐渐升高, 但各组间及与对照组间的差异不显著(P>0.05), 谷草转氨酶(AST)和谷丙转氨酶(ALT)随着豆粕替代比例增加而逐渐升高, 但豆粕蛋白替代比例小于80%时差异不显著(P>0.05)。豆粕蛋白替代比例为100%时AST、ALT活性显著高于其余各试验组(P<0.05)。说明饲料中豆粕替代一定比例的鱼粉蛋白可促进齐口裂腹鱼的生长, 提高对饲料蛋白的代谢和免疫能力, 但豆粕替代鱼粉蛋白比例超过80%则可引起肝损伤或组织病变。在本试验条件下, 综合考虑其生长指标、体成分及免疫指标, 齐口裂腹鱼的饲料中豆粕对鱼粉蛋白的最大替代比例为80%, 当其替代比例为34.25%~45.46%时可获得最佳生长效果。     

Partial replacement of fishmeal by soybean meal in diets for juvenile cobia (Rachycentron canadum)

An 8‐week feeding experiment was conducted in floating cages (1.5 × 1.0 × 2.0 m) to determine the potential use of defatted soybean meal (roasted and solvent‐extracted) as a partial replacement of fishmeal in the isonitrogenous (approximately 450 g kg^?1 CP [crude protein]) diet for juvenile cobia with an initial average weight of about 8.3 g. Diets were formulated to include 0, 100, 200, 300, 400, 500 and 600 g kg^?1 (diets D0, D10, D20, D30, D40, D50 and D60, respectively) of fishmeal protein being substituted by defatted soybean meal without methionine supplementation. The results showed that weight gain rate decreased significantly when the replacement level of fishmeal protein was increased from 400 g kg^?1 to 500 g kg^?1, and the D60 diet was the lowest in all groups. These results indicate that up to 400 g kg^?1 of fishmeal protein can be replaced by defatted soybean meal without causing significant reduction in growth. Feed conversion ratio (FCR) and protein efficiency ratio (PER) were significantly affected by the replacement level of fishmeal protein being substituted by defatted soybean meal, when the replacement level of fishmeal protein was 200 g kg^?1 (diet, D20), FCR was the lowest and PER was the highest. There were no significant differences in the moisture, lipid, crude protein and ash content in whole body and muscle, while lipid content in liver increased as the dietary soybean meal replacement levels increased. There were significant differences in haemoglobin, haematocrit, red blood cell, plasma glucose and triglyceride concentration in fish fed diets with different soybean meal replacement levels. Results of this trial indicated that the optimum level of fishmeal protein replacement with defatted soybean meal, determined by quadratic regression analysis was 189.2 g kg^?1, on the basis of maximum weight gain.     

Haematological and biochemical characteristics of two aquacultured carnivorous cyprinids,topmouth culter Culter alburnus (Basilewsky) and yellowcheek carp Elopichthys bambusa (Richardson)

The haematological and biochemical characteristics of two healthy farmed cyprinids, the topmouth culter Culter alburnus and yellowcheek carp Elopichthys bambusa, were investigated in this study. Erythrocytes, thrombocytes, lymphocytes, monocytes and granulocytes (i.e. neutrophils and eosinophils) were observed in these two fish. Every type of these cells (excluding the erythrocyte and lymphocyte) showed similar sizes in the topmouth culter and yellowcheek carp. Thrombocytes and neutrophils were the two most abundant leucocytes in the topmouth culter while thrombocytes and lymphocytes were the two most frequent leucocytes observed in the yellowcheek carp. The erythrocyte counts, haemoglobin concentrations and values of serum glucose in these two fish were high. There were significant differences in the leucocyte counts, haemoglobin concentrations, mean cellular haemoglobin contents, mean cell haemoglobin concentrations and values of serum glucose, triglyceride, total bilirubin, alkaline phosphatase and chlorine between the topmouth culter and the yellowcheek carp. The information of haematology and blood biochemistry obtained here would be useful for the prevention and diagnosis of diseases of farmed topmouth culter and yellowcheek carp.     

Effect of partial replacement of dietary fish meal by soybean meal with betaine attractant supplementation on growth performance and fatty acid profiles of juvenile rainbow trout (Oncorhynchus mykiss)

This study was conducted to investigate the effects of dietary incorporation of soybean meal for fish meal replacement and supplementation of betaine as an attractant on growth performance and fatty acid profiles of rainbow trout (Oncorhynchus mykiss). Juvenile trout were fed practical diets, with increasing soybean levels and betaine supplementations. The experimental diets consisted of a control diet with fish meal as the sole protein source (control) and no attractant, 25% soybean‐1% betaine diet (SBM25‐B1), 50% soybean‐2% betaine diet (SBM50‐B2), and 50% soybean‐0% betaine diet (SBM50‐B0). Average body weight was 12.69 ± 0.16 g at the beginning of experiments. Following 54 days feeding programme with experimental diets, average body weights reached 47.45 ± 1.22 g, 58.11 ± 1.77 g, 56.34 ± 1.87 g and 53.76 ± 1.74 g in the control, SBM25‐B1, SBM50‐B2 and SBM50‐B0 groups respectively. As compared with control treatment, significant differences were observed in weight gain, specific growth rate and feed intake of 1% betaine treatment at 25% soybean‐meal‐incorporated diet (p < .05), but no differences were observed in feed conversation ratio and survival rates (p > .05). Compared with the control treatment, betaine‐supplemented groups had significantly higher total saturated fatty acid contents (p < .05). On the other hand, the control treatment showed a significantly higher level of monounsaturated fatty acid than the betaine‐supplemented groups (p < .05). Significant differences were observed in fatty acid profile of 1% betaine‐supplemented group (p < .05) compared with the control. Present findings revealed that 1% betaine supplementation with dietary incorporation of soybean meal at 25% level positively influenced growth performance, feed utilization and fatty acid profiles of rainbow trout juveniles.     

豆粕替代鱼粉对红螯螯虾幼虾生长、肌肉组成和消化酶活力的影响

为探讨红螯螯虾幼虾的饲料豆粕替代鱼粉的适宜替代量,配制5种不同替代水平(0、40%、60%、80%和100%)的等氮等能饲料,饲喂初重(0.53±0.06)g的红螯螯虾幼虾8周,测定其生长性能、肌肉组成、肝胰腺消化酶活力及抗氧化活力。结果显示,豆粕替代鱼粉对螯虾存活率没有显著影响;与对照组相比,豆粕替代鱼粉的替代量为40%~80%时,红螯螯虾幼虾的增重率和特定生长率没有显著变化;替代量为100%时,螯虾增重率和特定生长率显著下降,螯虾肌肉的蛋白质含量呈现一定程度的下降;豆粕替代鱼粉对螯虾肌肉的脂肪和灰分含量没有显著影响;随着替代量的增加,螯虾肝胰腺胰蛋白酶活力呈现下降的趋势,当替代量为100%时,胰蛋白酶活力显著下降;豆粕替代鱼粉对螯虾肝胰腺脂肪酶、淀粉酶和超氧化物歧化酶(SOD)活力均没有显著影响;替代量为100%时,螯虾肝胰腺总抗氧化活力(T-AOC)显著下降。结果表明,豆粕替代鱼粉的替代量为40%~80%时,对螯虾的生长性能、肌肉组成、消化酶活力和抗氧化活力均没有显著影响,替代量为100%时,显著抑制螯虾的生长、胰蛋白酶活力和T-AOC。根据本试验结果,建议红螯螯虾幼虾饲料中豆粕替代鱼粉的替代量为80%。     

复合蛋白源替代鱼粉对中华绒螯蟹幼蟹生长性能、生理代谢和生化组成的影响

文章研究了复合蛋白源替代饲料中不同水平(0%、16.67%、33.33%、50%和66.67%,分别记为饲料1~#～5~#)的鱼粉对中华绒螯蟹(Eriocheir sinensis)幼蟹成活、生长、生理代谢和生化组成的影响。结果显示:1)随着鱼粉替代水平增加,幼蟹终末体质量、增重率、特定生长率和肝胰腺指数均呈先升后降的趋势,2~#组最高(P<0.05);2)肝胰腺中的谷草转氨酶、谷丙转氨酶活力和丙二醛含量均为4~#组最高,而超氧化物歧化酶活力在1~#组最高(P<0.05);血清中的谷丙转氨酶活力在5~#组最高,甘油三酯含量和超氧化物歧化酶活力则以4~#组最高,而丙二醛含量在2~#组最高(P<0.05);3) 1~#组躯体的粗蛋白和粗脂肪含量均显著高于其他组,而总碳水化合物含量在2~#组最高(P<0.05)。躯体半胱氨酸含量在4~#组最高,而其他氨基酸与总氨基酸含量均在2~#组最高(P<0.05)。结果表明,饲料中过高的鱼粉替代水平(33%～67%)会降低中华绒螯蟹幼蟹生长性能和躯体营养物质的积累,对生理代谢产生不良影响,建议中华绒螯蟹幼蟹饲料中复合蛋白源替代鱼粉的比例为16.67%。