The effects of vitamin E on non-specific immune response of the juvenile soft-shelled turtle <Emphasis Type="Italic">Pelodiscus sinensis</Emphasis>   总被引：1，自引：0，他引：1  

Xian-Qing?Zhou  Cui-Juan?NiuEmail author  Ru-Yong?Sun 《Fisheries Science》2005,71(3):612-617

ABSTRACT:   This study was conducted to determine the effect of dietary vitamin E supplements on non-specific immune responses in juvenile soft-shelled turtles. Turtles were fed diets supplemented with vitamin E at 0 (control), 50, 250, 500, 1000 and 5000 mg/kg, respectively, for 4 weeks. Results showed that blood cell phagocytosis and serum bactericidal activity were significantly improved in turtles from two diets (250 and 500 mg/kg vitamin E supplementation), while had no significant improvement in turtles from the three remaining diets (50, 1000 and 5000 mg/kg vitamin E supplementation) when compared to turtles from the control group. Serum bacteriolytic activity in turtles from diets with 50, 250, 500 and 1000 mg/kg vitamin E supplementation were higher than activity levels quantified for the control group, but no significant difference was observed between the 5000 mg/kg vitamin E supplementation diet and the control diet. The results suggest that vitamin E has an upper and lower threshold for improving non-specific immune function in soft-shelled turtles, and the optimal supplementation may be between 250 and 500 mg/kg.  相似文献   

Measurements of auditory sensitivity in common carp <Emphasis Type="Italic">Cyprinus carpio</Emphasis> by the auditory brainstem response technique and cardiac conditioning method   总被引：2，自引：0，他引：2  

Takahito?KojimaEmail author  Hirosuke?Ito  Tomoyuki?Komada  Toru?Taniuchi  Tomonari?Akamatsu 《Fisheries Science》2005,71(1):95-100

ABSTRACT:   Recently, the non-invasive auditory brainstem response (ABR) technique has been applied to the determination of hearing sensitivity in fish. The technique has some advantages over, and methodological differences from, the classical techniques. The auditory thresholds of common carp were measured by the ABR technique. The classical method was applied to measure cardiac response by electrocardiogram (ECG) after conditioning with electric shock. The most sensitive frequency obtained by ABR was 505 Hz, and by ECG, 1000 Hz. The shapes of the audiogram obtained by ABR and ECG were similar, though threshold levels in both audiograms differed from each other. Furthermore, audiograms obtained by using behavioral techniques were compared with those taken by the ABR and ECG techniques to assess the validity of the ABR technique for testing fish hearing sensitivity. The measured threshold levels increased in the order of behavioral, ABR, and ECG techniques, in the range below 1000 Hz.  相似文献   

三沙湾海域化学需氧量（COD）分布特征及相关性分析     

黄东仁  丁光茂 《福建水产》2014,(6)

2012年5月和11月对三沙湾海域水质化学需氧量( COD)进行大面积调查研究,结果表明,2012年三沙湾海域COD含量变化范围为0．52~2．13 mg/L,平均含量为0．94 mg/L;水平分布特征呈西北侧向东南水域逐渐递减的趋势,白马港海域COD含量最高;秋季高于春季;平均COD含量能达到一类海水水质标准要求;化学需氧量与活性硅酸盐、无机氮、总氮及悬浮物呈极显著正相关;与pH值、盐度呈极显著负相关。  相似文献   

Expression of gonadotropin genes in Manchurian trout <Emphasis Type="Italic">Brachymystax lenok</Emphasis> and production of recombinant gonadotropins     

Eunju?Choi  Hyeyeon?Ko  Jihye?Shin  Mi-Ae?Kim  Young?Chang?SohnEmail author 《Fisheries Science》2005,71(6):1193-1200

  相似文献   

Dietary habits of grazers influence their suitability as biological controls of fouling macroalgae in ex situ mariculture     

Chin Soon Lionel Ng  Tai Chong Toh  Kok Ben Toh  James Guest  Loke Ming Chou 《Aquaculture Research》2014,45(11):1852-1860

The dietary habits of the sea urchin Salmacis sphaeroides and the gastropod Trochus maculatus in ex situ mariculture were examined. Fouling algal assemblages on terracotta tiles were exposed to the grazers and compared. Except for Day 0, the assemblages on Days 2, 13 and 27 differed significantly across treatments. S. sphaeroides rapidly consumed most algae, leaving an assemblage dominated by turf algae and bare tile. T. maculatus primarily fed on green filamentous algae, resulting in an even distribution of other algal functional groups, while control tiles were dominated by green filamentous algae. Using three representative fouling algae species (Bryopsis corymbosa, Hypnea spinella and Lobophora variegata), the consumption rates of both grazers and dietary preferences of S. sphaeroides were examined through a single‐diet and a choice experiment respectively. The single‐diet experiment revealed differential algal consumption rates for S. sphaeroides (H. spinella = B. corymbosa > L. variegata) and T. maculatus (B. corymbosa > H. spinella = L. variegata). The choice experiment showed that S. sphaeroides preferred H. spinella over the other two species. These experiments highlighted the importance of understanding the dietary habits of grazers as this has direct implications on their effectiveness as biological controls of fouling macroalgae in mariculture.  相似文献   

The effects of less-expensive plant protein sources replaced with soybean meal in the juvenile diet of grass carp (Ctenopharyngodon idella): growth, nutrient utilization and body composition     

Kenan K?prücü  Ebru Sertel 《Aquaculture International》2012,20(3):399-412

In this study, the effects of less-expensive protein sources replaced with soybean meal on growth performance, nutrient utilization and body composition of juvenile grass carp were investigated. For this purpose, a control diet containing 42% soybean meal was prepared. Cotton seed meal (CSM), sunflower meal (SFM) and corn meal (CM) were added to the experimental diets by replacing 100% of the soybean meal protein used in the control diet. All diets were iso-nitrogenous (40% crude protein) and iso-caloric (19.5?MJ?kg^?1 gross energy). Each treatment had three replicates, and 20 juvenile grass carps (3.5?±?0.1?g, initial weight) were located in per replicate. The fish were fed to satiety three times in a day during 3?months at 26°C of water temperature in glass aquarium (45 l). The results of the study showed that the weight gain (308.6?C448.6%), specific growth rate (1.56?C1.89%/day), feed conversion rate (1.2?C1.9), protein efficiency ratio (1.32?C2.08), and apparent digestibility coefficients of protein (80.5?C89%) or sum of amino acids (80.5?C88.9%) were not significantly affected by the experimental diets, except diet CM. All of these values obtained for the diet CM were significantly lower than those of fish fed on the control, CSM and SFM diets. However, there were no significant differences between the lipid digestibility of the diets, and crude protein, lipid, and gross energy contents in the whole body of fish in experiments. In conclusion, CSM and SFM diets were highly utilized by juvenile grass carp, but not CM diet. These results combined with the remarkable acceptability of diets containing high levels of plant protein ingredients with identical growth performances of juvenile grass carp show clearly that dietary soybean meal level can be considerably reduced without any adverse consequence in terms of somatic growth and nitrogen utilization.  相似文献   

Effects of cage netting colour and density on the skin pigmentation and stress response of Australian snapper Pagrus auratus (Bloch & Schneider, 1801)     

Ben J Doolan  Geoff L Allan  Mark A Booth  Paul L Jones 《Aquaculture Research》2008,39(13):1360-1368

The unnaturally dark pigmentation of cultured Australian snapper Pagrus auratus can be improved through dietary astaxanthin supplementation and by holding fish in tanks with a white background. The practical application of these laboratory‐based findings was examined with two experiments to establish if the advantages of transferring fish to light coloured tanks before harvest could be achieved on‐farm using white cages and to determine the effects of fish density on skin colour. For the first experiment, snapper (mean TL=29.7 cm) were transferred from a commercial snapper sea cage to black or white netted cages and fed diets supplemented with unesterified astaxanthin (supplied as Lucantin^® Pink, BASF) at 0 or 39 mg kg^?1 for 42 days. Skin colour was measured using the CIE (black–white), (green–red), (blue–yellow) colour scale. Snapper held in white netting cages became significantly lighter (higher ) than snapper held in black cages; however, values were not as high as previous laboratory‐based studies in which snapper were held in white plastic‐lined cages. Snapper fed astaxanthin displayed significantly greater and values, and total carotenoid concentrations after 42 days. In addition, total carotenoids were higher in fish from black than white cages. The second experiment was designed to investigate whether density reduced the improvements in skin colour achieved by holding fish in white coloured cages and whether cage colour affected stress. Snapper (mean weight=435 g) were acclimated to black cages and fed 39 mg kg^?1 astaxanthin for 44 days before transferring to black or white plastic‐lined cages at 14 (low), 29 (mid) or 45 (high) kg m^?3 for 7 days after which time skin colour, plasma cortisol and plasma glucose concentrations were measured. Skin lightness () was greater in snapper transferred to white plastic‐lined cages with the lightest coloured fish obtained from the lowest density after 7 days. Density had no effect on plasma cortisol or glucose levels after 7 days, although plasma cortisol was elevated in snapper from black cages. For improved skin colouration we recommend feeding unesterified astaxanthin at 39 mg kg^?1 for approximately 6 weeks and transferring snapper to white plastic‐lined cages or similar at low densities for short periods before harvest rather than producing fish in white netting sea cages subject to biofouling.  相似文献   

Effects of dietary astaxanthin concentration and feeding period on the skin pigmentation of Australian snapper Pagrus auratus (Bloch & Schneider, 1801)     

Ben J Doolan  Mark A Booth  Geoff L Allan  Paul L Jones 《Aquaculture Research》2008,40(1):60-68

A single‐factor experiment was conducted to investigate the effects of dietary astaxanthin concentration on the skin colour of snapper. Snapper (mean weight=129 g) were held in white cages and fed one of seven dietary levels of unesterified astaxanthin (0, 13, 26, 39, 52, 65 or 78 mg astaxanthin kg^?1) for 63 days. Treatments comprised four replicate cages, each containing five fish. The skin colour of all fish was quantified using the CIE L^*, a^*, b^* colour scale after 21, 42 and 63 days. In addition, total carotenoid concentrations of the skin of two fish cage^?1 were determined after 63 days. Supplementing diets with astaxanthin strongly affected redness (a^*) and yellowness (b^*) values of the skin at all sampling times. After 21 days, the a^* values increased linearly as the dietary astaxanthin concentration was increased before a plateau was attained between 39 and 78 mg kg^?1. The b^* values similarly increased above basal levels in all astaxanthin diets. By 42 days, a^* and b^* values increased in magnitude while a plateau remained between 39 and 78 mg kg^?1. After 63 days, there were no further increases in measured colour values, suggesting that maximum pigmentation was imparted in the skin of snapper fed diets >39 mg kg^?1 after 42 days. Similarly, there were no differences in total carotenoid concentrations of the skin of snapper fed diets >39 mg kg^?1 after 63 days. The plateaus that occurred in a^* and b^* values, while still increasing in magnitude between 21 and 42 days, indicate that the rate of astaxanthin deposition in snapper is limited and astaxanthin in diets containing >39 mg astaxanthin kg^?1 is not efficiently utilized. Astaxanthin retention after 63 days was greatest from the 13 mg kg^?1 diet; however, skin pigmentation was not adequate. An astaxanthin concentration of 39 mg kg^?1 provided the second greatest retention in the skin while obtaining maximum pigmentation. To efficiently maximize skin pigmentation, snapper growers should commence feeding diets containing a minimum of 39 mg unesterified astaxanthin kg^?1 at least 42 days before sale.  相似文献   

The relationship between water intake rates,paddy ponding depth,and farmers’ water management techniques     

Mitsumasa?AnanEmail author  Kozue?Yuge  Yoshisuke?Nakano  Tamotsu?Funakoshi  Tomokazu?Haraguchi 《Paddy and Water Environment》2004,2(1):11-18

Japanese farmers manage their irrigation water based on their past experiences and preferences, considering such factors as weather and available water (hereafter defined as empirical water management). They elaborately control the intake and drainage rates of their own paddy fields to maintain optimal ponding depths. But these well-managed systems will drastically change because of the decreasing number of farmers. Therefore, it is necessary to clarify if the optimal ponding depth will be maintained within the limits of traditionally-allowed water intake rate from the main river. The first objective of this study was the quantification of actual water use in the paddy fields, resulting from the farmers water management on the basis of their experience. The significance of the present water intake rate under empirical water management was studied for a paddy field command area of about 230 ha. Water intake rates and the water requirements of the whole area were investigated by measuring the flow rate at 17 points of irrigation and drainage canals. Characteristics of the farmers empirical water management were investigated by measuring the hourly changes in inflow and outflow rates for a sub-area using an automatic measurement system, and an inferential method of determining water management patterns for the paddy fields was proposed. The newly-proposed inferential method was introduced in the tank model, which expresses the characteristics of water management in the command area. The Shuffled Complex Evolution Algorithm (SCE-UA) method was used for optimizing the model parameters. It was proven that the model accuracy improved when the farmers empirical water management was taken into account. The optimal amount of water to be applied to the command area was quantified by the simulation. The second objective was to predict the effect of the decreasing number of farmers on future water use conditions. The simulated result indicates the difficulty of maintaining optimal ponding depth for the whole command area when the farmers empirical water management is not maintained. In other words, results indicated that efficient water use requires an automatic water management system or a new pipeline system to replace the farmers present empirical water management.  相似文献   

覆盖作物翻压对华北平原春玉米产量和土壤养分的影响          下载免费PDF全文

魏静  郭树芳  翟丽梅  刘泰  杨波  孙本华 《中国土壤与肥料》2020,(1):172-178

冬季覆盖作物-春玉米种植模式是减缓华北平原冬小麦减少导致的耕地裸露及其环境影响的新型农业生产方式,但其翻压后对华北平原下一季春玉米生长季作物产量和土壤养分及微生物学性质的影响研究鲜见。本研究以华北平原冬闲田-玉米(WFM)为对照,设置毛叶苕子-玉米(VrM)、二月兰-玉米(OvM)以及冬油菜-玉米(BcM)3个覆盖作物处理,通过盆栽试验研究了冬季种植覆盖作物翻压对玉米生长季土壤理化性质、微生物量和玉米生长特性的影响。结果表明:(1)翻压覆盖作物显著提高了玉米产量以及作物养分吸收量。与WFM处理相比,OvM处理秸秆产量和籽粒产量提高幅度最大,分别为33.3%和35.5%(P0.05);BcM处理地上部氮、磷、钾和地下部磷素吸收量显著提高(P0.05),分别为30.7%、74.7%、57.6%和171.4%。(2)翻压覆盖作物能显著提高0～10和10～20 cm土层有机质、碱解氮、有效磷、速效钾、全氮和全钾含量(P0.05)。此外,翻压覆盖作物能显著降低玉米幼苗期土壤NH_4~+-N和NO_3~--N含量(P0.05),范围为0.50～3.52和21.40～33.13mg·kg~(-1)。(3)在玉米的不同生育期,覆盖作物翻压处理的SMBC、SMBN和SMBP均显著高于冬闲处理(P0.05)。综合翻压覆盖作物对华北平原玉米产量及土壤理化性质和微生物量含量的影响,华北平原冬油菜-玉米和二月兰-玉米轮作模式效果较好。  相似文献