在饲料中添加柑橘或甜橙外果皮对鲤鱼诱食作用的比较研究

在基础饵料中不同量（０．０５％、０．１％、０．２５％、０．５％、１％、３％）的柑橘或甜橙外果皮,用记录仪记录鲤鱼啄咬饵料球的频率和力。表明,柑橘和甜橙外果皮是２种新的鲤鱼诱食物物质,而且二者对鲤诱食作用的效果基本相同,其适宜添加量分别为０．２５％或０．１％。     

饲料中添加不同诱食剂对南美白对虾生长和饲料消化的影响

两种等氮但不同鱼粉水平 (4 0 %和 35 % )的基础饲料中分别添加 0 2 %、 0 5 %甜菜碱、 0 2 %甜菜碱 +0 1%牛磺酸或一种市售添加剂配置成 8种实验饲料。饲料试验在循环系统的玻璃钢桶 (2 6 0L)中进行。结果显示饲料中添加不同诱食剂 ,有利于对虾的摄食和生长 ,甜菜碱诱食效果最佳 ,牛磺酸和甜菜碱的协同诱食效果并不明显。南美白对虾对无机盐、粗蛋白质有较高的表观消化率 ,但是粗脂肪的表观消化率较低只有 6 0 %左右。本研究表明甜菜碱是一种较好的诱食剂 ,其适宜添加量为 0 2 %。诱食剂在两种等氮等能但不同鱼粉水平 (4 0 %和 35 % )的饲料中作用并不明显 ,进一步研究诱食剂在鱼粉含量低、低蛋白饲料中的作用 ,研究南美白对虾脂类营养及调控机理十分必要     

甜菜碱对鲤鱼生长性能及饵料系数的影响

<正>本试验中发现饲料中添加不同比例的甜菜碱对鲤鱼特定生长率、增重、饵料系数都有一定的促进作用,而对成活率没有影响。同时也证明了添加甜菜碱后鲤鱼的采食量有所提高,有明显的诱食作用。     

铒料中添加卤虫粉养建鲤夏花当年养成试验

我区利用山西卤虫干粉在鲤鱼饵料中全部替代进口鱼粉已取得成功,并获得了较好的经济效益,现正逐步推）一应用。在此基础上,我们试验用卤虫在水产养殖中的高蛋白强诱食作用,在颗粒饵料中添加自虫粉喂养建鲤夏花,使其当年养成商品鱼,以期达到优质高产、降低成本、提高...     

牛磺酸对鲫鱼蛋白质消化吸收率的影响

选用牛磺酸作为饲料添加剂,以0.2%、0.4%、0.6%、0.8%的剂量将牛磺酸添加到基础饲料中,以基础饲料为对照,饲喂鲫鱼(45～52g/尾)15 d后,测定蛋白质消化吸收率.结果表明:牛磺酸可以显著提高鲫鱼对蛋白质的消化吸收率(p＜0.05).其中,添加0.60%组的效果最佳,比对照组提高6.65%.提高蛋白质消化率,是牛磺酸促进鱼体生长速度加快的主要原因之一.     

牛磺酸对鲫鱼蛋白质消化吸收的影响

选用牛磺酸作为饲料添加剂,以0.2%、0.4%、0.6%、0.8%的剂量将牛磺酸添加到基础饲料中,以基础饲料为对照饲喂鲫鱼(45￣52g)15d后,测定蛋白质消化吸收率。结果表明:牛磺酸可以显著提高鲫鱼对蛋白质的消化吸收率(P<0.05),其中,添加0.60%组效果最佳,比对照组提高6.65%。蛋白质消化率的提高,是牛磺酸促进鱼体生长速度加快的主要原因之一。     

DMPT等七种物质对淡水石斑鱼、泥鳅、金鱼诱食效果的初步研究

试验比较了DMPT、牛磺酸、甜菜碱、酵母浸膏、L-丙氨酸、甘氨酸、谷氨酰胺等七种物质对淡水石斑鱼、泥鳅、金鱼的诱食效果.结果表明:对淡水石斑鱼诱食效果的强弱顺序为DMPT>甘氨酸>甜菜碱>牛磺酸>L-丙氨酸,其中DMPT达到显著引诱水平(P<0.05);对泥鳅诱食效果的强弱顺序为L-丙氨酸>DMFT>牛磺酸>甜菜碱>甘氨酸;对金鱼的诱食效果强弱顺序为牛磺酸>甜菜碱>DMPT>甘氨酸.谷氨酰胺和酵母浸膏对三种动物均有抑制作用,L-丙氨酸对金鱼有抑制作用.     

牛磺酸对日本沼虾生长及酚氧化酶活性的影响

通过在饵料中分别添加不同含量的牛磺酸, 初步研究牛磺酸对日本沼虾生长及体内酚氧化酶活性的影响。结果表明, 在饵料中添加 0 .4% ~0. 8%的牛磺酸, 日本沼虾的增重率显著增加 (P<0 .05); 饵料中添加 0. 4%的牛磺酸, 日本沼虾肌肉中的酚氧化酶活性也显著升高 (P<0 .05)。说明饵料中牛磺酸的含量对日本沼虾的生长和免疫力存在显著影响, 以饵料中添加 0. 4 %的牛磺酸比较适宜。     

诱食剂NUTRI-TRACK对鲫鱼的诱食效果

以鲫鱼为实验对象,研究了诱食剂NUTRI-TRACK对鲫鱼的诱食效果。结果表明:饵料中添加诱食剂后能显著提高鲫鱼的增重率,显著降低饵料系数,显著提高饵料干物质和蛋白质的消化率;同时通过观察统计实验鱼进入实验区和对照区中的次数,证实NUTRI-TRACK对鲫鱼具有较好的诱食作用。     

国外简讯

甲基睾酮可抑制鲤鱼性腺发育本文讨论了用17α—甲基睾酮(17α—MT)抑制鲤鱼性腺发育,以促进其生长的效果。试验分对照、300ppm 处理、400ppm 处理三组进行,17α—MT 混在饵料中投喂。激素处理从一日龄幼苗开始至第三十天结束,然后用正常饵料(无激素饵料)喂养365天。结果表明.三种处理的成活率无显著差异,分别为83.3%、83.3%、95.0%;投喂激素饵料的鲤鱼生长速度显著快于对照     

The effect of dietary taurine on growth performance and liver histopathology in Persian sturgeon,Acipenser persicus (Borodin, 1897) fed plant‐based diet

This experiment was conducted to illustrate the effect of dietary taurine levels on Persian sturgeon, Acipenser persicus (mean weight of ~35 g) fed plant‐based diet. A basal diet containing low level of fishmeal (19%) was formulated containing 0.05% endogenous taurine (control diet). To this diet were added five levels of exogenous taurine: 0.25 (0.25T), 0.5 (0.5T), 0.8 (0.8T), 1.2 (1.2T) and 1.6% (1.6T). These diets were fed to the experimental fish for 42 days. Results showed that growth performance decreased and food conversion ratio increased as dietary taurine increased, although no significant difference was observed between the control and 0.25T treatments. Increased dietary taurine led to increased carcass moisture and decreased carcass lipid percentages. Feed intake was significantly and negatively correlated with dietary taurine. Carcass taurine content significantly increased with dietary taurine elevation up to 1.2% and then decreased. Hepatic taurine content showed a significant increase in 0.25T treatment and then decreased along with dietary taurine elevation and reached the control values at 1.6% taurine level. Dietary taurine elevation led to more hepatic damages compared to the control. In conclusion, although within the range reported for other studied fish, the tested taurine levels in this study might be supra‐optimal causing adverse effects in Persian sturgeon and further study with lower taurine levels is encouraged.     

牛磺酸缓解脂质氧化日粮对黄河鲤生长性能和肠道健康的负面影响

为了探究牛磺酸对脂质氧化饲料饲喂下黄河鲤生长性能和肠道健康的影响,实验先用等量的氧化鱼油（记为OFO）替换基础日粮（记为FO）中的新鲜鱼油,接着将不同含量（0.4%、0.8% 和1.2%）的牛磺酸分别加入OFO组饲料中（分别记为T0.4、T0.8和T1.2）,对初始体重为（8.74±0.01）g的黄河鲤进行为期10周的养殖实验。结果显示,与FO组相比,OFO组的终末体质量、增重率、特定增长率和饲料效率均显著降低。上述所有指标在T0.4、T0.8和T1.2组中均显著高于OFO组。另外,OFO组中肝胰脏抗氧化酶的mRNA表达水平显著低于FO组,而牛磺酸添加组中肝胰脏和肠道的抗氧化酶mRNA表达均有不同程度的上调。与FO组相比,OFO组中的肠道消化酶活性,肠绒毛高度、肠绒毛宽度和肌层厚度均显著降低,而在牛磺酸添加组中均得到提高。同样的,OFO组中肠道微生物组成的丰富度和多样性显著降低,条件致病菌丰度明显升高,而有益菌的丰度却有所下降,这些不良现象在牛磺酸组中均得到明显改善。研究表明,牛磺酸可缓解脂质氧化饲料对黄河鲤造成的生长性能抑制、肠道组织结构破坏、消化功能下降及肠道菌群紊乱等不良影响。结合本研究结果,在氧化脂质饲料中牛磺酸的建议添加剂量为0.4~0.8%。本研究为进一步探索牛磺酸对鱼类肠道的生物学功能奠定理论基础。     

牛磺酸对鲤生长及血清T_3、T_4含量的影响

用牛磺酸作为饲料添加剂,以0.2%、0.4%、0.6%、0.8%的剂量将牛磺酸添加到基础饲料中,以基础饲料为对照,饲喂重(40.73±3.92)g的鲤60 d后,测定鱼体的相对增重率、饲料系数、血清中三碘甲状腺原氨酸(T3)及甲状腺素(T4)的含量,结果表明:牛磺酸显著地提高鲤的生长速度和血清甲状腺素的含量(P<0.05),极显著地提高鲤的血清三碘甲状腺原氨酸的含量(P<0.01),对饲料系数没有显著影响(P>0.05)。血清T3、T4含量的提高,是牛磺酸促进鱼体生长速度加快的重要原因之一。     

饲料牛磺酸对尼罗罗非鱼生长、体成分及组织游离氨基酸含量的影响

本文探讨了饲料牛磺酸水平对尼罗罗非鱼幼鱼生长性能、体成分及游离氨基酸含量的影响。选用体重为5.89±0.03g的罗非鱼300尾,随机分为5个处理组,每个处理3个重复,每个重复20尾。在基础饲料中分别添加0、0.4%、0.8%、1.2%、1.6%的牛磺酸,配制成5种试验料,分别饲喂不同处理组的罗非鱼,饲养周期为56d。结果表明： 0.8%牛磺酸组罗非鱼增重率最高,且显著高于0%和1.6%组(P<0.05);饲料牛磺酸水平(0.4%-1.2%)显著提高了罗非鱼摄食率、肝脏指数和内脏指数,显著降低了饲料系数(P<0.05)。随着饲料牛磺酸水平的提高,鱼体粗蛋白质和粗脂肪含量随之升高,鱼体水分和粗灰分含量随之降低(P<0.05);以增重率为指标,通过二次曲线回归分析得出罗非鱼饲料牛磺酸最适需要量为0.75%。罗非鱼血清、肝脏、肌肉和全鱼中牛磺酸含量与饲料牛磺酸含量存在正相关关系,且牛磺酸添加组血清、肝脏、肌肉和全鱼牛磺酸含量显著高于对照组相(P<0.05)。罗非鱼肝脏和肌肉中游离氨基酸含量随饲料牛磺酸含量的增加均呈逐渐下降的趋势,且牛磺酸添加组肝脏和肌肉中游离氨基酸含量显著低于对照组(P<0.05)。     

Dietary taurine can improve the hypoxia-tolerance but not the growth performance in juvenile grass carp Ctenopharyngodon idellus

This study was conducted to evaluate the effects of dietary taurine, as a feed additive, on the hypoxia-tolerance and growth performance of the juvenile grass carp Ctenopharyngodon idellus, one of the most important and intensively cultured freshwater fish, with the largest production in China. Graded levels of taurine (0, 0.5, 1, 1.5, 2 and 2.5 g kg^–1 dry diet) were fed to grass carp juveniles (mean weight: 5.26 ± 0.03 g) for 8 weeks. The survival time during acute hypoxia increased as dietary levels of taurine increased, with the highest dose of taurine resulting in the best acute hypoxia-tolerance. The erythrocyte osmotic fragility in grass carp was significantly improved when dietary taurine level was at least 1.5 g kg^?1 diet and can be improved much more when dietary taurine level was up to 2.5 g kg^?1 diet. A significant correlation between hemolysis rate of the erythrocyte osmotic fragility test and the survival time of acute hypoxia (r = ?0.873, P = 0.023 < 0.05) strongly suggested that the biomembrane stabilization function of taurine may contribute to its role of enhancing acute hypoxia-tolerance in grass carp. Dietary taurine cannot improve growth performance of grass carp, but it can increase the value of mesenteric fat index, indicating that dietary taurine influences the lipid metabolism. This study provides valuable information to improve hypoxia-tolerance of grass carp.     

Effect of dietary taurine supplementation on growth performance,digestive enzyme activities and antioxidant status of juvenile black carp (Mylopharyngodon piceus) fed with low fish meal diet

An 8‐week feeding trial was conducted to determine the effects of dietary taurine supplementation on growth performance, activities of digestive enzymes, antioxidant status and the target of rapamycin (TOR) gene expression in black carp (initial body weight 5.94 ± 0.02 g) fed with low fish meal diet. Six isonitrogen and isolipidic diets were formulated. High fish meal–based diet (HFM) contained 20% fish meal and 24% soybean meal as a positive control. Fifty per cent of fish meal in HFM was replaced by soybean meal and were supplemented with 0, 0.05%, 0.1%, 0.2% and 0.4% dietary taurine respectively (designated as T_0.00 (a negative control), T_0.05, T_0.1, T_0.2 and T_0.4). The results showed that the partial replacement of fish meal by soybean meal without taurine supplementation resulted in a significant reduction in weight gain (WG), activities of amylase and lipase in intestine, superoxide dismutase (SOD) and glutathione peroxidase (GSH‐px) in serum, with a significant increase in feed conversion rate (FCR), the content of malonaldehyde (MDA), triglyceride (TG) and total cholesterol (TC) in serum. WG in groups supplemented with equal or above to 0.1% dietary taurine was significantly higher compared with T₀ group. With increasing levels of dietary taurine, the activities of amylase, lipase, GSH‐px and SOD and glutataione (GSH) content significantly increased (p < 0.05). FCR, the content of MDA, TG and TC in serum and crude lipid content in whole body were significantly reduced after taurine treatment (p < 0.05). In liver, TOR mRNA expression in groups with equal or above to 0.1% taurine was significantly higher than T₀ group (p < 0.05).     

Limiting Amino Acids in Practical Diets for California Yellowtail,Seriola lalandi

Three trials were run to identify the limiting dietary amino acids in practical, soy‐based formulations for California yellowtail juveniles. In the first trial, four diets were formulated with 20% fish meal and 43% soy protein concentrate. The basal diet was supplemented with methionine, lysine, and taurine (MLT), and each supplement was then individually deleted in three additional diets (LT, MT, and ML). A significant decrease in growth was only seen in fish fed the ML diet. The second and third trials were designed to test graded levels of dietary taurine and methionine, respectively. Dietary taurine ranged from 0.32 to 1.5%, and methionine levels ranged from 0.95 to 1.19% of the diet with constant levels of cysteine (0.73%). While weight gains were considered adequate to detect a dietary amino acid deficiency, there was no significant effect of graded levels of either taurine or methionine on final weights, growth rates, survival, or feed efficiency. In conclusion, the practical diets tested required taurine supplementations, but did not require lysine or methionine supplementation. While these data are insufficient to determine the taurine or methionine requirement of California yellowtail, it provides minimum levels likely to meet these requirements. Additional research is necessary to determine taurine and methionine requirements precisely in this species.     

Suitability of genetically modified soybean meal in a dietary ingredient for common carp Cyprinus carpio

The effect of genetically modified (GM) soybean meal (SBM) in a feed ingredient on growth performance of common carp was investigated in comparison to nonGM SBM. GM SBM was included at 34 and 48% in two experimental diets that were formulated with fish meal (FM) to obtain approximately 38% protein in diet. Two other experimental diets were formulated to contain the same levels of nonGM SBM. The diets were fed to juvenile common carp (22 g initial mean weight) for 12 weeks. The cauliflower mosaic virus (CaMV) 35S promoter fragment (205 base pairs) of the GM SBM was examined in fish muscle and blood samples at the twelfth week. From the twelfth week, the GM groups were fed with nonGM diets to determine the residual span of the transferred promoter fragment. There was no significant difference in growth and feed performance between GM and nonGM groups at two inclusion levels after 12 weeks. The CaMV 35S promoter fragment was not detected in fish muscles or blood receiving either level of GM SBM diet. The results demonstrated that the availability of GM SBM was similar to that of nonGM SBM and the GM SBM would be a suitable and safe ingredient in feed for common carp.     

Effects of dietary betaine in allogynogenetic gibel carp (Carassius auratus gibelio): Enhanced growth,reduced lipid deposition and depressed lipogenic gene expression

A 10‐week feeding experiment was conducted to evaluate the effects of supplemental betaine on growth performance, body composition and lipid deposition in allogynogenetic gibel carp. Four isoproteic (37% crude protein) and isolipidic (5% crude lipid) artificial diets with 0%, 0.08%, 0.4% and 2% betaine supplementation were formulated, and named VB₀, VB_0.08, VB_0.4 and VB₂, respectively. Each diet was fed in triplicate to fish about 10 g in weight. The results showed that 0.4% betaine supplementation significantly improved growth performance and reduced lipid content in the hepatopancreas, muscle and the whole body compared with the control group. Moreover, both fatty acid synthase and acetyl‐CoA carboxylase, two important lipogenic genes, showed significantly lower expression in the VB_0.4 group than in the control group, and a strong correlation was detected between lipid content and mRNA expression levels for FAS and ACC in the hepatopancreas. Taken together, appropriate (0.4%) betaine supplementation in the diet not only improved growth, but also reduced lipid deposition in allogynogenetic gibel carp, probably by diminishing lipogenic gene expression.