吉富罗非鱼对饲料中锌的需要量

为考察吉富罗非鱼(GIFT,Oreochromis niloticus)对饲料中锌的需要量,以蛋氨酸锌为锌源,配制锌添加水平分别为0,10,20,40,80,160 mg/kg的6组等氮等脂饲料(实测值分别为9.98,21.47,33.75,56.03,88.16,172.54 mg/kg),饲喂初始体质量为(84.44±3.04)g的吉富罗非鱼,试验鱼分为6组,每组3个重复,每个重复20尾鱼,养殖周期为10周。结果显示,随着饲料中锌含量的增加,吉富罗非鱼的增重率、特定生长率先显著升高,在锌含量达到33.75 mg/kg后趋于稳定,添加锌显著降低了饲料系数,提高了成活率。饲料锌含量对全鱼水分、粗蛋白及灰分含量无显著影响,显著降低了全鱼粗脂肪含量。饲料中添加锌对血清总胆固醇含量无影响,显著提高了血清碱性磷酸酶的活性,碱性磷酸酶活性在锌含量达到33.75 mg/kg后趋于稳定,血清甘油三酯含量,乳酸脱氢酶、谷草转氨酶和谷丙转氨酶活性则呈下降趋势。饲料锌含量显著影响脊椎骨、全鱼和肝脏锌的含量,脊椎骨和全鱼锌含量先线性上升,在锌含量达到56.03 mg/kg后趋于稳定,各组的肌肉锌含量无显著差异。以增重率、骨骼锌和全鱼锌含量为评价指标,根据折线回归分析得出,以蛋氨酸锌为添加锌源,吉富罗非鱼对饲料中锌的需要量分别为32.37、55.67和56.13 mg/kg。     

饲料中添加谷胱甘肽对吉富罗非鱼抗氧化和抗亚硝基氮应激能力的影响

选择初始体重(3.27±0.04)g的吉富罗非鱼(GIFT Oreochromis niloticus),分别投喂基础饲料和添加80、160、240、320和400 mg/kg谷胱甘肽(GSH)的试验饲料,记作G0、G80、G160、G240、G320和G400。49 d后,G320血清和G160、G240肝脏谷胱甘肽S-转移酶,G160、G240血清和G320肝脏谷胱甘肽还原酶,G240肝脏超氧化物歧化酶,G320血清和G240肝脏过氧化氢酶活性,G240～G400血清和G240肝脏总抗氧化能力,G320血清抗超氧阴离子活性,与对照组相比分别显著升高。G80～G320肝脏丙二醛含量显著低于对照组。在亚硝基氮应激96 h内,G320累积死亡率显著降低。结果表明,饲料中添加一定量的GSH能显著提高罗非鱼的抗氧化性能和抗亚硝基氮应激能力。     

饲料中添加L-肉碱对吉富罗非鱼生长、肝脏脂肪代谢及抗氧化能力的影响

分别在3组等氮等能的吉富罗非鱼(GIFT,Oreochromis niloticus)饲料中添加不同水平的L-肉碱[0(对照组)、150和300 mg/kg],试验选用初始体重为(8.21±0.33)g的幼鱼投喂9周,探讨L-肉碱对吉富罗非鱼生长、体成分、血清生化指标、肝脏脂肪代谢酶活性和抗氧化能力的影响。结果表明:添加150或300 mg/kg L-肉碱显著提高了罗非鱼增重率(WGR)和特定生长率(SGR),显著降低了实验鱼肝体比(HSI)和脏体比(VSI);添加150 mg/kg L-肉碱组WGR和SGR最高,HSI和VSI最低。添加150 mg/kg L-肉碱显著提高了鱼体肥满度(CF)。饲料系数(FCR)和存活率(SR)在对照组和实验组间无显著差异。添加150或300 mg/kg L-肉碱显著提高了鱼体肝脏中粗蛋白含量,添加150 mg/kg L-肉碱显著降低了肝脏粗脂肪含量。添加150或300 mg/kg L-肉碱时,血清甘油三酯(TG)含量显著降低,肝脏脂蛋白脂酶(LPL)、肝脂酶(HL)、总酯酶(LPL)和脂肪酶(LPS)活性显著上升,肝脏过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GSH-PX)活性显著增加,肝脏丙二醛(MDA)含量显著下降。添加300 mg/kg L-肉碱显著提高了鱼体肝脏超氧化物歧化酶(SOD)活性和溶菌酶(LZM)活性。综上,饲料中添加适量L-肉碱对提高吉富罗非鱼生长性能,促进其脂肪代谢和提高鱼体抗氧化能力有良好效果。基于L-肉碱对罗非鱼增重率和特定生长率的影响,推荐L-肉碱在吉富罗非鱼饲料中的添加量为150 mg/kg。     

低剂量糖蜜添加对吉富罗非鱼养殖水质和微生物代谢多样性的影响

为研究低剂量糖蜜添加对吉富罗非鱼(GIFT Oreochromis niloticus)养殖水体水质指标、水体微生物代谢多样性的影响。本实验选取初始体质量为(10±0.13) g的健康吉富罗非鱼,随机分为对照组(C)、10%糖蜜添加组(10S)、20%糖蜜添加组(20S)、40%糖蜜添加组(40S)4个组进行养殖实验,实验周期60 d,每7 d进行一次水质指标检测。运用Biolog-ECO法探究养殖水体微生物代谢多样性。实验结果显示：添加低剂量糖蜜可以有效降低罗非鱼养殖水体中无机氮的含量,对不同形态氮的去除率NO^-₃-N>NO^-₂-N>NH₃-N且实验组平均去除率显著高于对照组。通过Biolog微平板分析养殖水体微生物群落对31种碳源利用能力,AWCD值结果表明不同微生物对碳源的利用能力随时间增加而增加;低剂量糖蜜添加组的微生物活性明显高于对照组。进行主成分分析后发现微生物群落主要利用的碳源类型为氨基酸类、酯类和酸类。低剂量糖蜜添加组与对照组间微生物群落碳源代谢差异...     

蚕蛹替代鱼粉对吉富罗非鱼肌肉营养成分的影响

试验以300尾初始体重为(44.40±0.41)g的吉富罗非鱼(GIFT,Oreochromis niloticus)为研究对象,分别饲喂用蚕蛹(SP)替代0、25%、50%、75%和100%鱼粉(FM)的5种等氮(32%)等脂(5.5%)的饲料(分别命名SP0、SP25、SP50、SP75和SP100,基础饲料中含8%的鱼粉),每组3重复,每重复20尾鱼,在室内循环水养殖系统进行为期8周的生长试验,旨在探讨蚕蛹替代鱼粉对吉富罗非鱼肌肉营养成分的影响。结果表明:随蚕蛹替代水平上升,吉富罗非鱼肌肉粗蛋白、灰分、总氨基酸、必需氨基酸显著下降,肌肉粗脂肪含量无显著差异;较SP0组,SP100组肌肉总氨基酸和必需氨基酸分别下降3.99%和3.46%。随蚕蛹替代量增加,吉富罗非鱼肌肉C18∶3n-3和C20∶5n-3显著上升,C18∶2n-6显著下降;SP100组吉富罗非鱼肌肉C18∶3n-3和C20∶5n-3较SP0组分别上升105.33%和132.72%。结论:蚕蛹替代鱼粉后显著提高了吉富罗非鱼肌肉C18∶3n-3和C20∶5n-3含量,有利于生产富含n-3PUFA的鱼肉产品。     

饲料中添加红景天苷对尼罗罗非鱼血液学指标的影响

将红景天苷(Salidroside)作为免疫增强剂添加到水生生物饲料中,按0(对照组)、30、60和90μg/kg 4个梯度,添加到尼罗罗非鱼(Oreochromis niloticus)(117.2±4.53 g)饲料中,通过测定血液生理生化指标的变化,来评估红景天苷对尼罗罗非鱼血液免疫系统的影响。试验周期为45 d,每天投喂两次。结果表明,随着饲料中红景天苷添加量的升高,罗非鱼血液中红细胞压积、红细胞平均体积、平均红细胞血红蛋白含量以及肌酐水平显著升高(0<30μg/kg<60μg/kg<90μg/kg);90μg/kg组血液中的总蛋白含量显著高于其它各饲料组,血液中其它指标(白细胞计数、红细胞计数、红细胞分布宽度、血小板计数、白蛋白、谷丙转氨酶、尿素、血糖、球蛋白和尿素/肌酐)不受饲料中添加红景天苷的影响。实验结果表明尼罗罗非鱼饲料中红景天苷的适宜添加量为30μg/kg。     

饲料中添加中性蛋白酶对吉富罗非鱼生长和消化功能的影响

在吉富罗非鱼(Oreochromis niloticus)基础饲料中添加中性蛋白酶,添加量分别为0.00%、0.05%、0.1%、0.15%、0.2%和0.25%,研究添加后对吉富罗非鱼生长和消化功能的影响。结果表明,在饲料中添加0.1%~0.25%的中性蛋白酶,吉富罗非鱼的相对增重率和特定生长率显著提高,饲料系数显著降低(P<0.05);添加0.1%~0.2%的中性蛋白酶,显著提高饲料干物质表观消化率和粗蛋白表观消化率(P<0.05);添加量为0.1%~0.15%时,肝胰脏蛋白酶显著高于对照组(P<0.05),添加量为0.15%时,肠道蛋白酶活性显著提高(P<0.05)。综合鱼体相对增重率、特定生长率、饲料系数、消化器官消化酶活性等各项指标,吉富罗非鱼饲料中中性蛋白酶的添加量以饲料的0.1%~0.2%为宜。     

吉富罗非鱼(♀)与翘嘴鳜(♂)远缘杂交子代的遗传特征分析

为了探究吉富罗非鱼(Oreochromis niloticus,GIFT)(♀)与翘嘴鳜(Siniperca chuatsi)(♂)远缘杂交的可行性,对吉富罗非鱼(♀)×翘嘴鳜(♂)子代的胚胎发育、细胞遗传和分子遗传特征进行了初步研究.杂交子代的胚胎存活率仅为(0.34±0.13)％,通过流式细胞技术对正常存活个体进行...     

饲料中添加几丁聚糖对吉富罗非鱼幼鱼肝脏抗氧化力、血清激素及肌肉营养的影响

以吉富罗非鱼(Oreochromis niloticus)幼鱼为研究对象,探讨添加不同剂量的几丁聚糖对吉富罗非鱼幼鱼肝脏抗氧化力、血清生化与肌肉品质的影响。选择体重为(2.97±0.02)g的健康吉富罗非鱼375尾,随机分为5组,每组3个重复,每个重复25尾鱼,分别饲喂在基础日粮中添加0%(对照组)、1%、2%、3%和4%几丁聚糖溶液(有效成分为0.6%)。养殖63 d后,测定肝脏抗氧化性能、血清生化和激素水平以及肌肉中氨基酸与脂肪酸组成。结果显示,饲料中添加1%和2%几丁聚糖能显著提高血清C3、T3和Po水平,降低Lac与T4水平(P0.05)。同时,1%和2%添加组能显著降低肝脏MDA含量,提高SOD、CAT和GSH-Px活力(P0.05)。各实验组水分、灰分与粗蛋白含量无显著差异(P0.05)。然而,随几丁聚糖添加水平的增加,粗脂肪含量显著下降(P0.05)。各实验组氨基酸组成与脂肪酸组成无显著差异(P0.05);2%和3%几丁聚糖组氨基酸组成中EAA、DAA和TAA含量与PUFA含量略高于其它实验组。     

芦丁对吉富罗非鱼幼鱼组织切片及细胞凋亡的影响

在快速生长期日粮中添加较高浓度芦丁(0、0.1和0.3 g/kg),通过免疫、生殖器官组织切片和Tunel细胞凋亡分析,探究芦丁作为饲料免疫增强剂对吉富罗非鱼(Oreochromis niloticus)幼鱼组织切片及细胞凋亡的影响。结果表明低浓度芦丁会使肠道血小板增多,杯状细胞不规则;肝脏kupffer细胞少;并会造成肠道和肝脏细胞凋亡阳性率增高。高浓度芦丁组肝、脾脏出现细胞凋亡和含铁血黄素沉着;且造成肝脏和脾脏细胞凋亡阳性率增高;脾脏黑色素巨噬细胞中心少。此外,高浓度芦丁会对精巢、卵巢的发育起到抑制作用。芦丁作为水产行业免疫增强剂需慎用。     

Thermal and Chemical Properties of Gelatin from Tilapia (Oreochromis niloticus) Scale

ABSTRACT

Gelatin from the scale of Nile tilapia was extracted and characterized chemically, thermally, and structurally. Scales of Nile tilapia were subjected to acid pretreatment and extraction with water at 60°C. The process yielded 12.1% (m/m) on a dry basis. The 6.67% gelatin solution had a gel strength of 233.5 ± 14g. The amino acid composition revealed that 20.02% was comprised of imino acids and glycine (34.49%) as the most abundant amino acids. The scale gelatin had α1, α2, and β subunits and was thermally stable up to 200ºC. The Fourier transform infrared spectrum showed absorption in the regions of amides A, I, II, and III. The characterization of tilapia scale gelatin showed that the obtained product was similar to commercial gelatin, thereby demonstrating its potential application.     

Cortisol Response of Nile Tilapia,Oreochromis niloticus (L.), to Temperature Changes

Abstract

Nile tilapia, Oreochromis niloticus (L.), is a commercially-valuable fish species with high nutritional value. As a result of the intensive aquaculture of this species, handling, transport, and environmental changes that causes stress on these fish are unavoidable. The objective of this study was to determine the effects of gradual and acute temperature changes on juvenile tilapia. No significant difference (P > 0.05) was found among serum cortisol levels in juvenile tilapia when the water temperature was gradually increased from 27°C to 32°C, or 40°C, and maintained for 1 hour, although the levels were five times pretreat-ment levels. When tilapia acclimated to 27°C were subjected to 18°, 27°, 30°, 32°, 34°, 36°, 38°, or 40°C water for 10 minutes in a water bath, followed by a recovery period of 10 minutes at 27°C in the original aquaria, no significant difference (P > 0.05) in cortisol levels was observed among treatments except for significantly elevated levels at 38°C and 40°C. When tilapia acclimated to 27°C were subjected to the same temperature exposures but given a recovery period of 60 minutes at 27°C in the original aquaria, there was no significant (P > 0.05) increase in cortisol levels in tilapia among treatments from 18° to 36°C; but there was a significant (P > 0.05) increase between values from those treatments at 38° and 40°C. Acute temperature changes initiated the cortisol response as early as 10 minutes in fish following exposure to 38°C or 40°C and resulted in significant increases in the 38°C and 40°C treatments following 1 hour of recovery at 27°C. These results have implications for the management of tilapia during bacterial challenge, vaccination, and handling and transport during aquacultural activities.     

尼罗罗非鱼淀粉酶性质的初步研究

研究了尼罗罗非鱼(Oreochromis niloticus)肝脏淀粉酶的基本性质及金属离子对该鱼淀粉酶活性的影响。结果表明:罗非鱼淀粉酶活力的最适pH是6.5,最适底物浓度是2%。研究金属离子对该鱼淀粉酶活力影响,一价金属离子K+、Li+、Na+对酶活力影响较小;二价金属离子Cu2+对酶活力具有抑制作用,Zn2+对酶活力无明显影响;三价金属离子Al3+对酶活力具有抑制作用,但效果不是很强烈,Fe3+对酶活力具有明显的激活作用;碱土金属Mg2+、Ca2+对淀粉酶活性有激活作用,而Ba2+对酶具有抑制作用;重金属离子Cd2+、Pb2+有明显的抑制作用。     

棉酚对罗非鱼（Oreochromisniloticus）离体精子毒性作用的研究

新鲜采取的尼罗罗非鱼精液在加入棉酚的精子保存液中28℃下培养。高达10mM 的乙酸棉酚也不影响精子在一小时内的存活率。罗非鱼精子的存活率在培养三小时后存活率显下降，而低浓度棉酚（25－100μM）显提高罗非鱼精子的 存活率。 本对上述实验结果进行了讨论。     

三种生态环境下尼罗罗非鱼免疫因子的比较

随机选取海水池塘(盐度28)和淡水池塘养殖及水库天然增殖的3种不同生态环境下、体质量为200~500g的尼罗罗非鱼为研究材料,采用生物化学方法测定3种生态环境尼罗罗非鱼血清中碱性磷酸酶、酸性磷酸酶、过氧化物酶、谷胱甘肽还原酶的活性和蛋白质量浓度。结果显示,3种生态环境中罗非鱼血清中碱性磷酸酶和酸性磷酸酶活力差异不显著(P0.05),其余各组间罗非鱼血清中过氧化物酶和谷胱甘肽还原酶的活性及血清蛋白质量浓度差异显著(P0.05),酶活力和蛋白质量浓度依次为:水库海水池塘淡水池塘。试验结果表明,水库天然增殖的尼罗罗非鱼具有较高的磷酸酶活性。     

尼罗罗非鱼肠道淀粉酶高产菌株的筛选及耐酸、耐高温特性的研究

研究了从健康罗非鱼肠道中筛选出的活力为195 U/ml的淀粉酶高产菌株的耐酸耐高温能力。结果表明,该菌株最高耐受温度为80℃,20 min;在50~60℃时稳定性强,可保持正常生长,维持高菌体量;最适生长pH值为6,在强酸性条件下能存活,并维持缓慢生长。由此表明,该菌株在微生态饲料添加剂生产上具有重要潜在价值。     

Comparison of Stunning Methods on the Physicochemical Properties of Frozen Nile Tilapia (Oreochromis niloticus) Fillets

This study compares how CO₂ narcosis and thermal shock affect the physicochemical aspects of Nile tilapia fillets held frozen (?18°C) for up to 6 months. The characteristics of tilapia fillets subjected to CO₂ narcosis were those of higher lightness and whiteness and lower redness. The hardness values of fillets of tilapia subjected to thermal shock were lower than those subjected to CO₂ narcosis. During frozen storage to both treatments, the drip loss, denaturation of myosin, and lipid oxidation increased, while fillet water holding capacity and hardness decreased. The physicochemical properties of frozen fillets of tilapia stunned by CO₂ narcosis were considered more desirable; therefore, the method can be a potential replacement to thermal shock.     

木薯粉在罗非鱼饵料中的适口性研究

选择健康的吉富罗非鱼为试验鱼,比较不同水平木薯粉之间的诱食效果以及木薯粉与豆粕、次粉的适口性,评价木薯粉在罗非鱼饵料中的应用效果。结果表明,(1)40%、30%木薯粉组的诱食活性显著高于10%、20%木薯粉组(p0.01),40%与30%木薯粉之间没有显著差异(p0.05)。(2)罗非鱼对木薯粉与豆粕、次粉的适口性依次为豆粕木薯次粉。     

Improving low‐temperature stress tolerance of tilapia,Oreochromis niloticus: A functional analysis of Astragalus membranaceus

A 54‐day experiment was conducted to investigate the effects of dietary supplementation of Astragalus membranaceus extract powder (AMEP) on the low temperature tolerance of genetically improved farmed tilapia, Oreochromis niloticus. The base diet was supplemented with 0.0% (NC), 0.1% (NP0.1), 0.2% (NP0.2), and 0.4% (NP0.4) AMEP. Tilapia with an initial body weight of 21.35 ± 0.17 g were fed three times a day for 14 days at 30°C and then fed for 40 days while the water temperature decreased at a rate of 0.5°C/day. The results showed that survival, final weight, and the rate of weight gain in fish in the NP0.1, NP0.2, and NP0.4 groups were higher than those of fish in the NC group. The contents of glucose, triglyceride, cholesterol, and nitric oxide in the serum of fish fed diets supplemented with AMEP were all significantly lower than those of fish in the NC group. In contrast, fish fed with AMEP‐supplemented diets had higher liver superoxide dismutase, glutathione peroxidase and catalase activities, and lower malonaldehyde content than those of fish in the NC group at 10°C. The expression of the growth‐arrest‐specific 2 gene in the liver was significantly lower in the NP0.2 and NP0.4 groups than in the NC group. The results of this study demonstrated that the optimal level of AMEP supplementation was 0.2% under the conditions used in the current study. Optimum dietary AMEP can promote growth performance and facilitate the survival of tilapia under low‐temperature stress.     

尼罗与奥利亚罗非鱼对池塘蓝藻水华及水质影响的研究

利用尼罗罗非鱼和奥利亚罗非鱼进行了池塘抑藻试验,采用血球计数板测定水体中的微囊藻密度,并对水体理化性质进行了检测分析。试验结果表明,罗非鱼能有效消减水体中蓝藻生物量,降低水体藻毒素浓度,并对水体TN、TP产生一定影响。其中奥利亚罗非鱼试验组蓝藻初始密度为1．53-108cells／L,下降至0．86-108eells／L,降低43．79％;尼罗罗非鱼组蓝藻初始密度为1．54-108cells／L,下降至O．51×108cells,L,降低66．88％。水体总磷含量无显著变化,总氮含量有所下降,水体微囊藻毒素MC—LR含量随着蓝藻密度的下降而降低,并讨论了尼罗与奥利亚罗非鱼摄食抑制蓝藻的摄食抑制及其对水质的影响。