共查询到19条相似文献，搜索用时 453 毫秒
1.
饲料脂肪水平对梭鱼脂肪沉积、脂肪代谢酶及抗氧化酶活性的影响 总被引：10，自引：5，他引：5
为了探讨饲料脂肪水平对梭鱼(Chelon haematocheilus)脂肪沉积、脂肪代谢酶及抗氧化酶活性的影响,选取360尾平均体质量为(5.4±0.2)g的梭鱼鱼种,随机分为6组,每组3个重复,每个重复20尾鱼,分别投喂脂肪含量为2.71%、5.79%、8.23%、11.85%、14.39%、16.91%的6组等氮饲料,饲养60 d,测定相应生物学指标及酶活。研究结果表明,随着脂肪水平的升高,肝体指数、脏体指数显著升高(P<0.05),肥满度8.23%组最大,其显著高于2.71%组(P<0.05);梭鱼全鱼、肝脂肪含量显著升高(P<0.05),14.39%组全鱼脂肪含量最高,16.91%组肝脂肪含量最高。饲料脂肪水平对肝脂肪代谢酶有显著影响(P<0.05),其中脂蛋白酯酶(LPL)、肝酯酶(HL)、总酯酶(GE)活性随着饲料脂肪水平的升高显著增高(P<0.05),16.91%组显著高于2.71%、5.79%、8.23%组(P<0.05);苹果酸脱氢酶活性呈显著下降趋势(P<0.05);血液中甘油三酯(TG)、总胆固醇(CHO)、游离脂肪酸(EFA)有升高趋势,但各组差异不显著(P>0.05);脂肪水平16.91%组高密度脂蛋白胆固醇(HDL)含量最高,显著高于脂肪水平2.71%的组(P<0.05);肝胰脏超氧化物歧化酶(SOD)活性随着饲料脂肪水平的升高呈先上升后下降的趋势,8.23%组活性最高,丙二醛(MDA)含量16.91%组显著高于其他5组(P<0.05)。结果显示,肝是梭鱼脂肪沉积的主要场所,肝脂肪沉积比肌肉更敏感,高脂肪饲料还使脂肪分解酶的活性增强,血脂含量增加;适宜的饲料脂肪水平可提高梭鱼的抗氧化能力,脂肪水平过高则会导致抗氧化能力下降。 相似文献
2.
为探究复方中草药对许氏平鲉(Sebastes schlegelii)幼鱼生长与免疫酶活性的影响，选取144尾重量相近的许氏平鲉幼鱼分为4组，每组设3个平行，每个平行12尾鱼。将黄芪、当归、红枣、干姜、甘草、白术六种中草药等比例混合后超微粉碎，分别按质量百分数0(对照组)、1%、2%、3%加入到许氏平鲉基础饲料中进行投喂，试验为期42 d。结果表明：与对照组相比，各试验组许氏平鲉的过氧化氢酶(CAT)、总超氧化物歧化酶(T-SOD)活性显著提高(P<0.05),1%组的增重率、特定生长率和摄食率显著高于其他组(P<0.05),总抗氧化能力(T-AOC)无明显差异(P>0.05),而饲料系数低于对照组及3%组(P<0.05)。综上所述，在饲料中添加复方中草药对许氏平鲉生长和免疫功能有显著提升作用，建议的最适添加量为1%。 相似文献
3.
人工隐蔽物及投喂频率对许氏平鲉幼鱼生长和行为的影响 总被引：1，自引：1，他引：0
室内水槽实验条件下研究了许氏平鲉(Sebastes schlegelii)幼鱼(15.24 g±2.9 g)在不同光照条件下对3种人工遮蔽物的行为反应。在此基础上,通过7周的养殖实验研究了不同放养密度下(800 ind/m3,1 200 ind/m3,1 600 ind/m3),隐蔽物、投喂频率(1次/d、2次/d、3次/d、4次/d)对许氏平鲉幼鱼(0.50 g±0.02 g)生长、摄食和行为的影响。结果表明:1)实验采用的3种隐蔽物对许氏平鲉幼鱼均有明显的诱集作用,其中扇贝笼改造的隐蔽物S1诱集效果最好。2)遮光条件可以提高隐蔽物区域幼鱼的分布率,但与自然光处理组差异不显著(P0.05)。3)在实验设定的密度范围内,许氏平鲉幼鱼的终末体重、日增重率、特定生长率随密度的增大而升高。无隐蔽物条件下,低密度组的日增重率和特定生长率与中高密度组差异显著(P0.05),终末体重则显著低于高密度组(P0.05);隐蔽物的设置显著提高了中、低密度组许氏平鲉幼鱼的终末体重(P0.05),高密度组幼鱼的特定生长率和饲料转换率也有显著提高(P0.05)。4)放养密度和隐蔽物对于许氏平鲉幼鱼的生长离散影响显著(P0.05),随着放养密度的增大,幼鱼的体重变异系数呈逐渐增大趋势;相同放养密度下,放置隐蔽物的各组幼鱼生长离散均小于未放置组,其中低密度组间差异极显著(P0.01),中密度组间差异显著(P0.05)。5)3种放养密度下饱食投喂频率为1次/d处理组幼鱼的体重变异系数显著大于其他各组(P0.05),饱食投喂频率大于2次/d时,各处理组幼鱼生长离散无显著差异(P0.05)。研究结果表明,对于体重0.5~5.8 g的许氏平鲉幼鱼,当放养密度为1 200 ind/m3条件时,通过投放人工隐蔽物,选取2次/d的饱食投喂频率,可显著降低生长离散水平,并使幼鱼获得较好的生长。本研究旨在为许氏平鲉健康苗种培育及规模化生产提供科学指导和技术支撑。 相似文献
4.
饲料脂肪水平对俄罗斯鲟幼鱼生长、血液生化指标及抗氧化性能的影响 总被引：2，自引：0，他引：2
以鱼油、豆油、亚麻籽油等比例混合,配成脂肪含量分别为5.45%(L1)、7.00%(L2)、10.44%(L3)、14.37%(L4)、16.34%(L5)、18.91%(L6)及20.15%(L7)的等氮饲料,饲喂俄罗斯鲟(Acipenser gueldenstaedtii)幼鱼[(6.20±0.02)g]8周。实验结果表明,L3组的终末体质量、增重率最大,但与L2组间无显著差异(P0.05),L3组的蛋白质效率显著高于其它组(P0.05),且饲料系数最低。L6和L7组终末体质量、增重率和蛋白质效率显著低于L2和L3组(P0.05)。将幼鱼的增重率与饲料脂肪水平进行回归分析,得出俄罗斯鲟幼鱼在饲料脂肪水平为10.69%时生长最佳。随着饲料脂肪水平的升高,各组鱼的肝体比和体粗脂肪有上升趋势,其中肝体比在饲料脂肪含量大于14.37%时显著增大(P0.05)。血清中的甘油三酯、胆固醇含量也随脂肪水平升高而显著提高(P0.05),提示脂肪过高会影响俄罗斯鲟幼鱼的生长,降低蛋白质效率,导致脂肪在体内的过量积蓄。L7组鱼血清中高密度脂蛋白胆固醇含量最高,而L1组鱼的低密度脂蛋白胆固醇含量最高。肝脏脂蛋白酯酶活性随饲料脂肪水平的提高而升高,脂肪酸合成酶活性则随脂肪水平升高而降低,提示饲料脂肪水平的提高会促进鱼体脂肪的分解代谢。肝脏丙二醛含量和超氧化物歧化酶活性均随着饲料脂肪水平的提高显著升高(P0.05),表明脂肪含量过高会导致脂质过氧化,引发机体抗氧化酶活性的升高。综合俄罗斯鲟幼鱼的生长、血液指标及抗氧化性能,建议生产中将幼鱼的饲料脂肪水平控制在7.00%~10.69%。 相似文献
5.
盐度胁迫对许氏平鲉血液免疫酶活力的影响 总被引：7，自引：1，他引：6
研究了急性、慢性盐度胁迫对许氏平鲉体重及血液免疫相关酶活力的影响。慢性盐度胁迫实验表明,在盐度5的水体中,许氏平鲉体重增长率为负值,其余各盐度组(10、20、40)的生长指标与自然海水组(盐度33)差异不显著(P>0·05);随海水盐度的降低,许氏平鲉的溶菌酶活力逐渐上升,但当盐度降至5时,其活力与自然海水组无显著性差异;血液中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)的活力随海水盐度降低呈逐渐上升趋势。急性盐度胁迫实验证实,在盐度5、10的急性胁迫初期,许氏平鲉血液的各项免疫酶活力波动较大。溶菌酶活力在胁迫24h时达到峰值,之后逐渐下降;血液SOD活力在96h检测过程中呈高低起伏变化趋势;血液CAT活力在胁迫初期持续降低,12h后逐步稳定在较低水平,显著低于胁迫前血液CAT活力(P<0·05)。 相似文献
6.
为研究环境与摄食因素对人工鱼礁区不同体长许氏平鲉分布的影响,采用2017—2018年山东省近岸3处鱼礁区环境和渔业资源的调查数据,利用变异系数CV均值将样本的体长分为10组,每组体长间隔为33 mm,并使用Bray-Curtis相似性指数比较不同海域许氏平鲉体长组成的相似性;运用去趋势对应分析(DCA)、典范对应分析(CCA)分析各环境要素对不同体长组许氏平鲉分布的影响;运用胃含物分析法分析许氏平鲉的食物组成。结果显示,西霞口与长岛鱼礁区样本体长组成相似性指数为70.66%,前三岛鱼礁区与西霞口鱼礁区、长岛鱼礁区的相似性指数较低,分别为54.94%和59.46%;大体长(299～365mm)许氏平鲉的分布与水深、水质指数(WQI)和化学需氧量(COD)相关性较大,喜好水深较深、营养丰富的水域;小体长(35～200 mm)许氏平鲉喜好水深较浅,水质好的水域。大体长(200～365 mm),高龄(2～3龄)的个体主要摄食鱼类、虾类和蟹类,优势饵料为鱼类(IRI为65.94%);小体长(35～200 mm),低龄(0～1龄)的个体主要摄食虾类和蟹类,优势饵料为虾类(IRI为45.69%)。研究表明,在浅水区域投放幼鱼保护型鱼礁,为幼鱼提供庇护所;将捕捞作业集中在深水区,减少对许氏平鲉小体长个体的兼捕,可以达到针对性增殖、保护许氏平鲉资源的目的。 相似文献
7.
为研究精氨酸(Arg)对患有豆粕型肠炎(SBMIE)的许氏平鲉(Sebastes schlegelii)生长性能、Arg代谢、肠道组织结构、抗氧化性能、肠道紧密连接蛋白基因(occludin、clnd15和zo-1)及炎症因子基因(il-1β、il-8、il-15和tlr8)和抗炎因子基因(il-12b)表达量的影响,以(54.97±0.12) g已诱导出SBMIE的许氏平鲉为研究对象,基础配方中添加30%豆粕,以Arg 0添加为对照组(D0),添加1%、2%和3% Arg为处理组(D1、D2和D3),配制4组等氮等能的实验饲料,每组3个重复,每个重复40尾鱼,进行为期6周的养殖实验。结果显示,D2和D3组实验鱼增重率显著升高(P<0.05),各处理组肝体比和脏体比均显著低于D0组,肥满度显著高于D0组(P<0.05);处理组血清二胺氧化酶(DAO)、诱导型一氧化氮合成酶(iNOS)活性及一氧化氮(NO)含量显著降低(P<0.05),D2和D3组总一氧化氮合成酶(T-NOS)活性显著降低(P<0.05);Arg显著提高了实验鱼肠道皱襞高度(P<0.05);处理组肠道总抗氧化能力显著升高,并以D2组最高(P<0.05),D2和D3组丙二醛含量显著降低(P<0.05);相比较D0组,各处理组occludin mRNA相对表达量显著上调,D2组clnd15 和D1组zo-1 mRNA相对表达量显著上调(P<0.05);处理组肠道il-1β、il-15和tlr8 mRNA相对表达量显著下调,il-12b mRNA相对表达量显著上调(P<0.05)。综上所述,在本实验条件下,高豆粕饲料中添加Arg能显著提高SBMIE-许氏平鲉的生长性能和抗氧化性能,改善Arg代谢和肠道组织结构,上调肠道紧密连接蛋白和抗炎因子基因相对表达量,下调炎症因子基因相对表达量。Arg (2%最佳)对许氏平鲉SBMIE具有修复作用。本研究为Arg修复SBMIE的机制提供了理论依据。 相似文献
8.
急性温度胁迫对妊娠期许氏平鲉血清皮质醇和血液生理指标的影响 总被引：2，自引：2，他引：0
为探究鱼类对温度突变水体的适应性和恢复性,将妊娠期许氏平鲉由正常水温(16℃)直接转入高温(25℃)和低温(7℃)水体,急性胁迫2h后再恢复至16℃,检测恢复期第0、6、12、24、48和72h时妊娠期许氏平鲉血清皮质醇和血液生理指标的变化情况。结果显示,25℃急性胁迫导致2尾鱼发生产仔行为;25℃和7℃急性胁迫后的恢复过程中,血清皮质醇(COR)、血糖(GLU)、球蛋白(GLB)、丙氨酸氨基转移酶(GPT)、天门冬氨酸氨基转移酶(GOT)和白细胞(WBC)水平均显著升高(P<0.05),总蛋白(TP)、白蛋白(ALB)、总胆固醇(TC)及甘油三酯(TG)水平显著降低(P<0.05),血清Ca2+、Mg2 和P水平无显著变化;红细胞(RBC)和血红蛋白(HGB)水平在25℃胁迫后明显上升(P<0.05),而在7℃胁迫后显著下降(P<0.05)。与急性低温胁迫相比,急性高温胁迫对妊娠期许氏平鲉机体生理情况的影响更显著。除COR和无机离子外,多个生理指标在72h后仍未恢复至正常水平。研究表明,急性温度胁迫导致妊娠期许氏平鲉生理状况和代谢水平受到显著影响,甚至发生提前产仔行为。在养殖生产中,对于进入生殖期的雌鱼,应密切监测水温变化,尤其是水温的上升,以减少温度应激导致的妊娠损伤。 相似文献
9.
为探明许氏平鲉低氧耐受能力及低氧胁迫过程中其血液生理生化指标和鳃组织形态结构变化,本研究分析了许氏平鲉临界氧分压(Pcrit)和失去平衡点(LOE)时溶解氧含量,观察了低氧胁迫和恢复溶解氧过程中呼吸行为和呼吸频率的变化,分析了血液生理[红细胞数目(RBC),白细胞数目(WBC),血红蛋白(Hb),红细胞积压(HCT)]、生化[葡萄糖、皮质醇]指标以及鳃组织形态学和鳃组织气体交换率(PAGE)变化。结果显示,在温度18 ℃、盐度30,pH值7.85的条件下,许氏平鲉[(88.01±5.34) g] Pcrit和LOE溶解氧含量分别为(3.96±0.11)和(2.60±0.21) mg/L。随着水体中溶解氧含量下降,血浆皮质醇和葡萄糖分别在LOE和Pcrit达到最高。许氏平鲉血液RBC、Hb和HCT在LOE达到最高。低氧过程中,许氏平鲉呼吸频率和PAGE分别于Pcrit和LOE达到最高,且低氧导致许氏平鲉鳃小片长度(SLL)、间距(ID)、周长显著增加;鳃小片宽度(SLW)则随水中溶解氧含量下降而变窄,在LOE处达到最小值。许氏平鲉鳃小片末端膨大、基质肥大、增生比例在低氧过程中显著增加。恢复正常溶解氧24 h后,上述各项检测指标恢复正常,与对照组无显著差异。实验中对照组各项指标无显著变化。研究表明,许氏平鲉对水体低溶解氧变化反应敏感,低氧应激导致其血液生理生化相关指标和鳃小片形态发生显著改变,恢复正常溶解氧24 h后可以显著缓解低氧胁迫应激。相关结果为研究许氏平鲉低氧耐受生理调控机制和高效健康养殖提供了理论依据和技术支撑。 相似文献
10.
卵胎生许氏平鲉胚胎离体培养及发育形态学 总被引：1，自引：0，他引：1
为了探讨许氏平鲉的离体培养发育形态学并设计出最适的体外培养液,以海水生理盐水为主要配方,设为对照(第一组),分别加入1%许氏平鲉血清(第二组),1%许氏平鲉卵巢组织匀浆(第三组),1%胎牛血清(第四组),1%许氏平鲉血清+1%许氏平鲉卵巢组织匀浆(第五组),共形成5组不同的离体培养液。分2次从妊娠许氏平鲉卵巢中获得处于不同发育阶段的胚胎,分别为高囊胚期、晶体出现期,在上述5种不同的培养液中培养,观察记录发育状况。结果发现,胚胎在体外培养的初始阶段为高囊胚期时,虽然在5组培养液中都能发育到十六肌节期,但是每组的发育时序有很大差别,第五组发育状况最好,发育最快,为60 h。第四组发育最慢,为67 h。其余组的发育时间介于第四组和第五组之间;当初始阶段为晶体出现期时,第五组中的胚胎发育速率最快,为57 h,并且有最高的孵化率,为80%。第二组虽然有很快的发育速率,但其孵化率最低,为40%。研究表明,在体外培养条件下,许氏平鲉的受精卵发育至破膜时约200 h,且第五组(1%许氏平鲉血清+1%许氏平鲉卵巢组织匀浆)是使许氏平鲉胚胎离体发育最快的培养液。 相似文献
11.
饲料脂肪水平和投喂频率对大黄鱼生长、体组成及脂肪沉积的影响 总被引：3，自引：2，他引：1
本实验以我国重要的海水养殖鱼类大黄鱼[初始体质量(13.57±0.33)g]为研究对象,在浮式网箱中进行为期8周的摄食生长实验,探讨饲料脂肪水平和投喂频率对大黄鱼生长、体组成及脂肪沉积的影响。采用3×2双因子实验设计,其中饲料脂肪水平分别为9%、12%和15%,投喂频率分别为2次/天和1次/天。结果表明:投喂频率对大黄鱼特定生长率(SGR)和饲料效率(FER)均有显著影响(P<0.05),而饲料脂肪水平仅对FER有显著影响(P<0.05)。2次/天投喂组的大黄鱼末体质量和SGR均显著高于1次/天投喂组,而饲料效率显著低(P<0.05)。在2次/天投喂时,各个饲料脂肪水平对SGR和FER没有显著影响(P>0.05)。而在1次/天投喂时,随着饲料脂肪水平的提高,SGR和FER均显著提高(P<0.05)。2次/天投喂组的大黄鱼全鱼水分含量显著低于1次/天投喂组,而粗脂肪含量显著高(P<0.05)。大黄鱼全鱼粗脂肪含量随着饲料脂肪水平的增加而显著升高(P<0.05)。然而在1次/天投喂时,饲料脂肪水平未对全鱼体粗脂肪含量产生显著影响(P>0.05)。大黄鱼的肝脏和肌肉脂肪含量、肝体比(HSI)以及脏体比(VSI)受到了饲料脂肪水平的显著影响(P<0.05)。在2次/天投喂时,肝脏和肌肉脂肪含量、HSI以及VSI随饲料脂肪水平的升高而显著增加(P<0.05);而在1次/天投喂时,各个饲料脂肪组大黄鱼肝脏和肌肉脂肪含量、HSI以及VSI均无显著差异(P>0.05)。饲料脂肪水平和投喂频率仅对大黄鱼的生长、饲料效率的影响存在显著的交互作用(P<0.05),而对大黄鱼体组成、形态学指标以及肝脏和肌肉脂肪含量无显著的交互作用(P>0.05)。 相似文献
12.
饲料蛋白质和脂肪水平对牛蛙生长性能的影响 总被引：1，自引：1，他引：0
为研究饲料中不同蛋白质和脂肪水平对牛蛙生长、体组成和肝脏健康的影响,以红鱼粉、豆粕和酪蛋白为蛋白源,鱼油和豆油为主要脂肪源,α-淀粉为主要糖源,微晶纤维素为填充剂,并补充无机盐和维生素等配制实验饲料。实验设3个蛋白水平(35%、40%和45%),每个蛋白水平下设4个脂肪水平(4%、7%、10%和13%),共12种饲料,饲料可利用能变化范围为12.4~17.8 kJ/g,蛋白能量比变化范围为21.9~32.0 mg/kJ。每种饲料设置3个重复,每个水族缸放养12只牛蛙[初始平均体质量为(91.5±1.1)g],每日饱食投喂2次,实验周期56 d。结果发现,饲料蛋白质和脂肪水平对牛蛙的存活率无显著影响,而13%脂肪组的牛蛙肝脏出现颜色不均一和肝体脆化无韧性的现象。饲料蛋白质和脂肪水平显著影响牛蛙的增重率、特定生长率、摄食率、饲料效率和蛋白质效率。其中,40%蛋白组牛蛙的增重率和特定生长率显著高于35%蛋白组,与45%蛋白组无显著差异。随着蛋白质水平的升高,饲料效率显著升高,而摄食率和蛋白质效率显著降低。随着脂肪水平的升高,增重率、特定生长率和摄食率显著升高,饲料效率、蛋白质效率和氮保留率无显著差异。饲料脂肪水平与牛蛙全体的脂肪含量和总能水平正相关,但不影响牛蛙全体的蛋白质含量。随着饲料脂肪水平的升高,牛蛙肝脏丙二醛含量显著升高,过氧化氢酶和脂蛋白酯酶活力先升高后降低。研究表明,牛蛙饲料适宜的蛋白质和脂肪水平分别为40%和7%,适宜蛋白能量比为27.7 mg/kJ。 相似文献
13.
甘草次酸对团头鲂生长、脂肪沉积与抗氧化功能的影响 总被引：3，自引：2，他引：1
为探讨甘草次酸对团头鲂生长、脂肪沉积和抗氧化功能的影响,选取均体质量为(15.63±0.04)g的团头鲂幼鱼420尾,随机分在15个网箱中,分别以甘草次酸水平为0、0.15、0.30、0.45和0.60 g/kg的5种饲料投喂8周。结果发现,饲料添加甘草次酸对团头鲂增重率、特定生长率、饵料系数没有显著影响(P0.05)。甘草次酸可以显著降低实验鱼脏体比、肝体比、腹脂率及肝脏脂肪含量(P0.05),但对全鱼体组成和肌肉脂肪含量无显著影响(P0.05)。比对血浆脂肪代谢酶可见,0.30~0.60 g/kg甘草次酸添加组血浆总胆固醇含量较对照组显著下降(P0.05);而甘油三酯、游离脂肪酸和高密度脂蛋白胆固醇含量无显著变化(P0.05)。肝脏中脂蛋白酯酶、肝酯酶和总酯酶活性在添加甘草次酸后显著降低(P0.05);0.30~0.60 g/kg甘草次酸添加组脂肪酶活性显著高于其他各组(P0.05)。饲料添加甘草次酸可以显著提高肝脏超氧化物歧化酶活性和还原型谷胱甘肽含量,降低丙二醛含量(P0.05)。研究表明,饲料中添加0.30~0.45 g/kg甘草次酸时,显著降低了团头鲂内脏团的脂肪沉积,改善了鱼体脂肪分布,这可能是由于甘草次酸加强脂解作用,提高脂肪代谢酶活性导致的;饲料中添加甘草次酸也可显著提高团头鲂的抗氧化能力。 相似文献
14.
Effects of dietary choline supplementation on growth performance,lipid deposition and intestinal enzyme activities of blunt snout bream Megalobrama amblycephal fed high‐lipid diet 
下载免费PDF全文
下载免费PDF全文 This study aimed to investigate the effects of dietary choline supplementation on growth, lipid deposition and intestinal enzyme activities of Megalobrama amblycephala. Fish were fed four diets with two lipid levels (50 and 150 g kg?1) and two choline supplementations (600 and 1600 mg kg?1) for 8 weeks. Feed conversion ratio (FCR), viscerosomatic index (VSI), hepatosomatic index (HSI), intraperitoneal fat (IPF) ratio, whole‐body and muscle lipid contents, intestinal lipase activities and lipoprotein lipase (LPL) activities all increased significantly (P < 0.05) as lipid levels increased, whereas the opposite was true for whole‐body and muscle moisture contents and intestinal amylase activities. VSI, IPF ratio and whole‐body lipid contents all decreased significantly (P < 0.05) with increasing dietary choline supplementations. Weight gain, muscle moisture content all increased significantly (P < 0.05) with increasing dietary choline supplementations when dietary lipid levels reached 150 g kg?1, whereas the opposite was true for FCR, IPF ratio, IPF and liver LPL activities. In addition, abnormal hepatocytes were found in the liver of fish fed 150 g kg?1 lipid with 600 mg kg?1 choline supplementation. The result of this study indicated that extra choline supplementation can improve growth performance, intestinal enzymes activities and reduce excessive lipid deposition of M. amblycephala fed high lipid. 相似文献
15.
Two feeding trials were conducted to determine the optimal dietary carbohydrate to lipid (CHO:L) ratio for juvenile and grower rockfish. Triplicate groups of juvenile (initial mean weight 3.6 g) and duplicate groups of grower (initial mean weight 166 g) were fed the five isonitrogenous (51% CP) and isoenergetic (4.0 kcal g?1) diets with the different CHO:L ratios (0.4–5.6 g:g) for 8 weeks respectively. The survival of juvenile and grower was above 93% and was not affected by the dietary CHO:L ratios. Weight gain of juvenile fed the diets with CHO:L ratios of 0.8 and 1.6 was significantly higher than that of the fish fed diets with CHO:L ratios of 2.8 and 5.6 (P<0.05). The feed efficiency and protein efficiency ratio of juvenile fed the diet with CHO:L ratio of 5.6 were the lowest among all groups (P<0.05). The daily feed intake of juvenile fed the diet with a CHO:L ratio of 5.6 was significantly higher than that of the other groups (P<0.05). The condition factors of juvenile fed the diets with CHO:L ratios of 0.8 and 1.6 were significantly higher than that of 5.6 (P<0.05). The crude lipid content of whole body, liver and viscera of juvenile decreased as the dietary CHO:L ratio increased, and the opposite was found for the moisture content. Weight gain, feed efficiency, daily feed intake, protein efficiency ratio and condition factor of grower were not affected by the dietary CHO:L ratio. Hepatosomatic and viscerasomatic indexes of grower were significantly influenced by dietary CHO:L ratio (P<0.05). Significant differences were observed in the lipid content of whole body and viscera of grower. Dietary CHO:L ratios significantly affected the major fatty acid composition of whole body in both juvenile and grower. The contents of 18:2n‐6 and 18:3n‐3 linearly decreased as the dietary CHO:L ratio increased, whereas the 20:4n‐6, 20:5n‐3 and 22:6n‐3 contents increased. Based on growth, feed efficiency and body composition, the optimal dietary CHO:L ratio was 1.6 for juvenile rockfish fed isonitrogenous (51% CP) and isoenergetic (4.0 kcal g?1) diets, and starch could partially replace lipids in the diets with CHO:L ratios ranging from 0.4 to 5.6 for grower. 相似文献
16.
Dietary lipid requirements of larval genetically improved farmed tilapia,Oreochromis niloticus (L.), and effects on growth performance,expression of digestive enzyme genes,and immune response 下载免费PDF全文
下载免费PDF全文 The present study was performed to investigate the effects of dietary lipid level on growth performance, antioxidant defense, and mRNA levels of digestive enzymes and immune genes in larval genetically improved farmed tilapia (Oreochromis niloticus). The results show that larvae fed lipid levels of 4–11.5% had greater weight gain (WG), feed efficiency, protein efficiency ratio and survival than larvae fed the other dietary lipid levels (P < 0.05). No difference whole‐body crude protein, ash or moisture contents were found between treatments (P > 0.05) but lipid contents increased as dietary lipid level was increased. The 8% and 11.5% dietary lipid levels had stimulatory effects on trypsin mRNA level compared with those of larvae fed the 15% and 18.5% lipid diets. Intestinal and liver amylase mRNA levels decreased in larvae fed the 18.5% lipid diet, following the decrease in dietary starch. Analysis of the secondary curve equation for WG indicated that the optimal dietary lipid level in larval tilapia was 8.56%. In addition, the 4–11.5% lipid levels improved superoxide dismutase and glutathione peroxidase activities and increased mRNA levels of heat shock protein70, hepcidin antimicrobial peptide‐1, and C‐type lysozyme in the liver of larvae (P < 0.05). A 192‐h Streptococcus iniae challenge study was conducted after the 35‐day feeding trial, and the results showed that post‐challenge mortality of larvae fed the 11.5% lipid level was the lowest and enhanced the immune activities. 相似文献
17.
本实验以初始体重为(5.85±0.19)g红白锦鲤(Cyprinus carpio L)幼鱼为实验对象,研究在螺旋藻添加量为12%时,饲料脂肪水平对锦鲤生长、饲料表观消化率、肠道消化酶和血液生化指标的影响。实验设5.36%、7.74%、10.52%、12.85%、15.45%5个脂肪梯度,每组设3个重复,每个重复10尾鱼,表观饱食投喂60 d。结果显示:脂肪水平为5.36%～10.52%,锦鲤增重率(BWG)、特定生长率(SGR)随脂肪水平的升高而升高,均在脂肪水平为10.52%时,达到最大值。实验鱼血清谷丙转氨酶(ALT)随脂肪添加比例呈现先下降再升高的趋势,脂肪水平为12.85%后,血清ALT显著升高(P<0.05),脂肪水平为15.45%时,血清GLU浓度显著升高(P<0.05),而甘油三酯(TG)、总胆固醇(CHOL)随脂肪水平的升高各实验组间无显著性差异(P>0.05)。结果表明,螺旋藻添加量一定时,锦鲤适宜脂肪添加水平为10.52%。 相似文献
18.
Murat Arslan Konrad Dabrowski Sylvana Ferrer Mariola Dietrich Gustavo Rodriguez 《Aquaculture Research》2013,44(5):760-771
To evaluate protein and lipid requirement of South American catfish surubim (Pseudoplatystoma sp.) juveniles, nine semi‐purified diets containing three levels of protein (40%, 45% and 50%) and three levels of lipid (12%, 16% and 20%) were tested. After 8‐week feeding trial, body weight increase averaged 2124.3 ± 295.7%. Growth performance was significantly affected by dietary level of protein (P < 0.05). At the 40% protein level, increasing level of dietary lipid had a positive effect on final individual mean weight (protein sparing effect). Whole body protein and moisture contents were affected by the dietary level of lipid (P < 0.05). Whole body lipid content positively correlated with the level of dietary lipid (P < 0.05). Cannibalism related mortality was observed despite rearing fish in 24 h dark. Fatty acid composition of fish was affected by the dietary lipid level (P < 0.05). Polyunsaturated fatty acids increased with the increasing level of dietary lipid while saturated fatty acids and monounsaturated fatty acids decreased. Trypsin activity in the digestive tract of surubim was influenced by dietary levels of protein and lipid (P < 0.05). Our preliminary results suggest that the optimum protein/lipid ratio might be close to 45/16% for surubim juveniles. 相似文献
19.
Effect of dietary protein and lipid levels on growth and body composition of juvenile turbot was determined at optimum salinity and temperature conditions of 17 g L?1 and 19.2 °C, respectively, by using 3 × 2 (protein levels: 550, 600 and 650 g kg?1; lipid levels: 69 and 168 g kg?1) factorial design with three replications of each. Fish were hand‐fed to satiety twice daily throughout the feeding trial. Weight gain and specific growth rate of fish were significantly (P < 0.05) increased with increased dietary lipid level, but not by dietary protein level. Daily feed intake was significantly (P < 0.05) affected by both dietary protein and lipid levels. Feed efficiency ratio and protein efficiency ratio were significantly (P < 0.05) affected by dietary lipid level, but not by dietary protein level. Moisture content of whole body was significantly (P < 0.05) affected by dietary lipid level, but not by dietary protein level. Crude lipid content of whole body was significantly (P < 0.05) affected by dietary lipid level, but not by dietary protein level. Significantly higher 20:5n?3, 22:6n?3 and n?3 highly unsaturated fatty acids were observed in turbot fed the low lipid diet than fish fed the high lipid diet in all protein levels, but significantly lower 18:2n?6 was observed in fish fed the former compared with the latter. In considering results of growth, specific growth rate and efficiency of feed, optimum dietary protein and lipid levels for juvenile turbot seemed to be 550 and 168 g kg?1 of the diet, respectively, under optimum salinity and temperature conditions. 相似文献