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排序方式: 共有407条查询结果,搜索用时 31 毫秒
1.
为了探讨添加红枣提取物对促进虹鳟(Oncorhynchus mykiss)机体健康的可能性,选取体长为7.2~8.4 cm的健康虹鳟,随机分成4个试验组,分别投喂红枣提取物添加量为0%(对照组)、0.25%、0.50%和1.00%的等氮等脂饲料,饲养56 d,养殖结束后测定12项血清生化指标和头肾的6个免疫相关基因mRNA表达量。结果显示:与对照组相比较,血清中肌酐(CREA)和尿素氮(BUN)含量三个红枣提取物组均出现极显著下降;谷丙转氨酶(GPT)活性在0.50%和1.00%组极显著下降,谷草转氨酶(GOT)活性也在0.50%和1.00%组出现了一定程度下降,但差异不显著;酸性磷酸酶(ACP)和碱性磷酸酶(AKP)活性无显著变化;总蛋白(TP)和白介素6(IL-6)含量在0.25%组出现显著增加;溶菌酶(LZM)活性三个红枣提取物组均显著升高;超氧化物歧化酶(SOD)活性在0.50%组极显著增加;补体4(C4)和肿瘤坏死因子(TNF-α)含量在0.25%和0.50%组均极显著增加。在头肾中,与对照组相比,SOD、白介素1β(IL-1β)和补体3(C3)基因表达量在0.50%和1.00%组均为显著或极显著上调;Factor H基因表达量在0.50%组显著上调;过氧化氢酶(CAT)和LZM基因表达量在0.50%和1.00%组仅出现差异不显著上调。上述结果表明,在虹鳟饲料中添加一定量的红枣提取物,可以起到促进肾功能,保护肝脏和提高其非特异性免疫功能的作用。 相似文献
2.
G. Power 《Ecology of Freshwater Fish》1992,1(1):12-25
Abstract– Juvenile chinook salmon in the Waitaki River, New Zealand and demonstration channels, living at about 16°C, increased in length by 0.32 mm day−1 between 4 November and 4 March. They gained weight quickly, accumulated large visceral fat deposits and had high conditions factors. At 1600 h, stomachs averaged half full. The number of prey tended to decline as the fish grew and consumed larger items. Initially the diet was based mainly on chironomid larvae, but by December it included a diversity of prey in more equal proportions. These included Deleatidium in the Waitaki; amphipods in the demonstration channels; various trichopterans, hemipterans, elmid beetles, zooplankton. terrestrial dipterans and a variety of other prey. There were significant differences between sites in numbers of prey consumed and these probably reflected differences in the benthos. Diets in the Waitaki differ from those in the Rakaia River and the food of juvenile salmon appears closely linked to the availability of a diverse range of possible prey. 相似文献
3.
Jamie S. Harmon Kim G. Michelsen Dr. Mark A. Sheridan 《Fish physiology and biochemistry》1991,9(4):361-368
Trialcylglycerol (TG) lipase was isolated and partially purified from rainbow trout liver. Triacylglycerol lipase activity was assayed by measuring14C-oleic acid release from14C-triolein.14C-oleic acid release was linear for up to two hours. Optimal activity occurred at pH 7.0 and 15°C. Most of the lipase activity was recovered in the cytosolic fraction. A 27,000-fold purification was achieved after Sepharose (Bio-gel A 0.5 M, 200–400 mesh) chromatography of a resuspended 20% ammonium sulfate fraction. The molecular weight of the trout hepatic lipase as determined by size-exclusion chromatography and by SDS-polyacrylamide gel electrophoresis was 40–43 kD. Lipase-mediated hydrolysis of TG resulted in the production of diacylglycerols, monoacylglycerols, and fatty acids. Kinetic analysis indicated that Vmax=0.016 nmol/h/mg protein and that Km=0.28 mM triolein. Lipolytic activity was enhanced in the presence of cAMP/ATP-Mg2+. These results suggest that the liver of trout possesses a neutral TG lipase that is responsible for mobilizing stored TG and is catalytically activated by phosphorylation.A part of this work was presented at the Annual Meeting of the American Society of Zoologists, December 26–30, 1990, San Antonio, TX. 相似文献
4.
Spatial and temporal landscape patterns have long been recognized to influence biological processes, but these processes often
operate at scales that are difficult to study by conventional means. Inferences from genetic markers can overcome some of
these limitations. We used a landscape genetics approach to test hypotheses concerning landscape processes influencing the
demography of Lahontan cutthroat trout in a complex stream network in the Great Basin desert of the western US. Predictions
were tested with population- and individual-based analyses of microsatellite DNA variation, reflecting patterns of dispersal,
population stability, and local effective population sizes. Complementary genetic inferences suggested samples from migratory
corridors housed a mixture of fish from tributaries, as predicted based on assumed migratory life histories in those habitats.
Also as predicted, populations presumed to have greater proportions of migratory fish or from physically connected, large,
or high quality habitats had higher genetic variability and reduced genetic differentiation from other populations. Populations
thought to contain largely non-migratory individuals generally showed the opposite pattern, suggesting behavioral isolation.
Estimated effective sizes were small, and we identified significant and severe genetic bottlenecks in several populations
that were isolated, recently founded, or that inhabit streams that desiccate frequently. Overall, this work suggested that
Lahontan cutthroat trout populations in stream networks are affected by a combination of landscape and metapopulation processes.
Results also demonstrated that genetic patterns can reveal unexpected processes, even within a system that is well studied
from a conventional ecological perspective. 相似文献
5.
为从蛋白质水平解释竹叶抗氧化物浸泡-乳清分离蛋白涂膜对富硒虹鳟的保鲜机理,实验将鲜活富硒虹鳟去除头、内脏和表皮,切块后浸泡在1.0%的竹叶抗氧化物(AOB)溶液中(去离子水作为对照),再进行乳清分离蛋白(WPI)溶液涂膜,25℃下鼓风吹干表面水分后置于4℃冰箱中贮藏1、4、7、10和13 d。测定鱼肉中肌原纤维蛋白和TCA-可溶性肽的含量、蛋白质的分子内价键,以及肌原纤维蛋白的总巯基含量、表面疏水性和二级结构,分析涂膜对冷藏富硒虹鳟蛋白质理化性质的影响。结果显示,冷藏期间,WPI组的肌原纤维蛋白含量和二级结构中β-折叠的含量显著高于对照组。冷藏1~7 d,WPI组的TCA-可溶性肽和二硫键含量以及表面疏水性指数(H0)显著低于对照组,总巯基含量呈相反趋势,但随着冷藏时间的延长这些差异逐渐减弱。冷藏13 d时,WPI组与对照组无显著差异。3个实验组中,1.0%AOB+WPI组的肌原纤维蛋白、总巯基、氢键、二级结构中α-螺旋和β-折叠的含量在冷藏期间最高,H0、TCA-可溶性肽、二硫键和二级结构中β-转角含量最低。WPI在鱼块表面形成一层薄膜,可... 相似文献
6.
The influence of dietary fat level and whole‐body adiposity on voluntary energy intake of juvenile rainbow trout Oncorhynchus mykiss (Walbaum) was examined using self‐feeders. Groups of lean fish [crude fat (CF) = 7%] and fat fish (CF = 11%), pretreated with a commercial diet with or without supplemental pollock oil, were self‐fed one of three fat level diets (CF = 8%, 13.5% and 19%) for 48 days at 17 °C. Final body weight (BW) and total digestible energy (DE) intake (kJ per fish) were positively affected by the initial BW. Relative to the initial BW, however, fat fish consumed less DE than lean fish. Although the effect of dietary fat level was not significant, percentage weight gain and daily DE intake per BW (kJ kg?1 BW day?1) of fat fish were significantly lower than those of lean fish (ancova with initial BW as a covariate, P < 0.05). Energy digestibility, feed efficiency and protein retention were improved with the dietary fat level; however, there was no difference resulting from body fat level. The whole‐body fat levels at the end of the experiment increased with the dietary fat level. Between groups self‐fed the same diet, fat levels of the initially fat fish were still higher than those of the lean fish. The results of the present medium‐term study suggest that rainbow trout adjust DE intake from diets with fat levels ranging from 8% to 19%. Although body fat level affects neither energy digestibility nor protein utilization, a high body fat level may reduce DE intake and consequently depress growth. 相似文献
7.
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9.
为研究复方中草药对鲁氏耶尔森菌(Yersinia ruckeri)感染虹鳟(Oncorhynchus mykiss)后其血液生化指标的影响,在虹鳟饲料中分别添加两种复方中草药(复方1组、复方2组),持续投喂28 d。在第28天感染鲁氏耶尔森菌,检测感染后72 h的血清生化指标,并统计各组存活率。结果显示:复方中草药组对虹鳟增重无抑制作用。添加复方中草药可提高虹鳟感染鲁氏耶尔森菌后的存活率,其中复方2组的保护效果最好。感染72 h后,复方2组总蛋白、白蛋白、球蛋白、甘油三酯、总胆固醇含量和碱性磷酸酶活性均高于对照组。复方2组谷丙转氨酶、谷草转氨酶活性低于对照组,乳酸脱氢酶活性显著低于对照组。复方1组和复方2组尿酸含量显著低于对照组。复方中草药组总胆红素、尿素氮、肌酐和血糖含量与对照组相比无显著性差异。结果表明,添加复方中草药能提高鲁氏耶尔森菌感染后虹鳟的存活率,其中复方2组的保护效果最好。 相似文献
10.
Climate variability and marine survival of coho salmon (Oncorhynchus kisutch) in the Oregon production area 总被引:1,自引:0,他引:1
Time series of adult recruitment for natural runs of coho salmon from the Oregon coastal region (1970–94) and marine survival of hatchery-reared coho salmon from California to Washington (1960–94) are significantly correlated with a suite of meteorological and oceanographic variables related to the biological productivity of the local coastal region. These variables include strong upwelling, cool sea surface temperature (SST), strong wind mixing, a deep and weakly stratified mixed layer, and low coastal sea level, indicating strong transport of the California Current. Principal component analysis indicates that these variables work in concert to define the dominant modes of physical variability, which appear to regulate nutrient availability and biological productivity. Multiple regression analysis suggests that coho marine survival is significantly and independently related to the dominant modes acting over this region in the periods when the coho first enter the ocean and during the overwintering/spring period prior to their spawning migration. Linear relationships provided good fits to the data and were robust, capable of predicting randomly removed portions of the data set. 相似文献