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1.
Dietary Lipid Levels Affect the Growth Performance,Lipid Deposition,and Antioxidative Capacity of Juvenile Scaleless Carp,Gymnocypris przewalskii,on the Qinghai‐Tibetan Plateau 下载免费PDF全文
Qiwei Qin Yanlin Tong Ruman Zhu Guoqian Xu Yuan Shi Jianquan Shi Rui Ma 《Journal of the World Aquaculture Society》2018,49(4):788-797
A 56‐d growth trial was conducted to evaluate the growth performance, lipid deposition, and antioxidative capacity of juvenile scaleless carp, Gymnocypris przewalskii, on Qinghai‐Tibetan Plateau. One‐year‐old juveniles (initial weight: 15.99 ± 0.02 g) were fed practical diets with different lipid levels of 4, 5.5, 7, 8.5, and 10%, respectively. Results showed that the best specific growth rate (SGR), feed conversion rate, and total antioxidative capacity (T‐AOC) in hepatopancreas were observed in fish fed the diet with 7% lipid level. Fish fed with high lipid diets (8.5 and 10%) had significantly higher condition factor and viscerosomatic index as well as lipid in muscle, intestine, mesenteric fat tissue, and whole body. Highest level of hepatopancreas lipase and lipoprotein lipases activities as well as malondialdehyde content and the lowest level of feed intake and T‐AOC content in hepatopancreas and intestine were also observed in fish fed with high lipid diets (8.5 and 10%) (P < 0.05). In conclusion, based on SGR and hepatopancreas T‐AOC content, dietary lipid requirement of juvenile G. przewalskii was estimated to be 7.35 and 7.39%, respectively. 相似文献
2.
Indices of the tomato seedling quality maintenance level after production before field planting were studied through simulated experiments, small--scale operation, indoor analyses and measurements, and field observation. The results showed that under simulated shipping and storage conditions, seedling quality change following different durations (days) of shipping and storage was correlated significantly or even very significantly with certain physiological and morphological indices. With various measured indices following different periods of shipping and storage treatment subjected to multinomial successive regressive correlation analysis, the principal factors influencing seedling quality maintenance level are identified to be chlorophyll content→dry short weight→ leaf freshness index in order of their importance. Significance analysis with multinomial fitted equation indicated that correlations between any one of above three factors and the growth index after field planting reached very significant difference level. 相似文献
3.
活性炭吸附痕量银的研究 总被引:3,自引:0,他引:3
在静态、动态吸附条件下,分别选用果壳类净水用活性炭和煤质净水用活性炭对胶片工业废水中的痕量银的吸附行为进行了研究.结果表明,废水中的银浓度可降至<50ppb,活性炭对银的吸附量达到3~5mg/g.微孔发达的活性炭更适于吸附废水中的痕量银.随着银液浓度的升高,银液量增大,活性炭吸附能力增加.银液的最佳吸附pH值是5. 相似文献
4.
根据大豆理想株型的概念,分析了大豆的主要生理性状和形态性状与产量的关系,并提出了大豆高产理想株型的合理构成,以期为大豆育种的田间选择和株型育种提供理论依据和实践指导。 相似文献
5.
牧压和肥力对亚热带山地牧草净生产的影响 总被引:4,自引:1,他引:3
在亚热带山地湿润环境条件下,研究牧压和土壤肥力对人工草地净生产的影响.三年试验结果表明,绵羊在轮牧下,产草量和磷肥对全年及各月牧草净生产具有显著影响.禁牧时,夏季地上生物量积累到一定程度后,只有很少量的净生产.放牧时,产草量在1000 kg DM/hm2左右时,净生产最大,当产草量低于300 kg DM/hm2以下时,净生产量则降低.每年施一次P2O5 36~60 kg/hm2,可以显著增加牧草净生产,尤以春末夏初时施肥更为显著.最低产草量出现在不施肥处理. 相似文献
6.
J. Müller 《Journal of Agronomy and Crop Science》1993,171(4):217-235
Dry Matter Production, CO2 Exchange, Carbohydrate and Nitrogen Content of Winter Wheat at Elevated CO2 Concentration and Drought Stress
Methods of mathematical modelling and simulation are being used to an increasing degree in estimating the effects of rising atmospheric CO2 concentration and changing climatic conditions on agricultural ecosystems. In this context, detailed knowledge is required about the possible effects on crop growth and physiological processes. To this aim, the influence of an elevated CO2 concentration and of drought stress on dry matter production, CO2 exchange, and on carbohydrate and nitrogen content was studied in two winter wheat varieties from shooting to milk ripeness. Elevated CO2 concentration leads to a compensation of drought stress and at optimal water supply to an increase of vegetative dry matter and of yield to the fourfold value. This effects were caused by enhanced growth of secondary tillers which were reduced in plants cultivated at atmospheric CO2 concentration. Analogous effects in the development of ear organs were influenced additionally by competitive interactions between the developing organs. The content and the mass of ethanol soluble carbohydrates in leaves and stems were increased after the CO2 treatment and exhausted more completely during the grain filling period after drought stress. Plants cultivated from shooting to milk ripeness at elevated CO2 concentration showed a reduced response of net photosynthesis rate to increasing CO2 concentration by comparison with untreated plants. The rate of dark respiration was increased in this plants. 相似文献
Methods of mathematical modelling and simulation are being used to an increasing degree in estimating the effects of rising atmospheric CO
7.
Abstract. Soil samples from a 32-year grassland field experiment were taken from 0–5, 5–10, and 10–15 cm soil depths in February 2002. Plots received annual treatments of unamended control, mineral fertilizer, three rates of pig slurry and three rates of cow slurry, each with six replicates. Samples were analysed for cation exchange capacity (CEC), exchangeable cations (Na+ , K+ , Ca2+ , Mg2+ ), pH and Olsen P. Exchangeable sodium percentage (ESP) was calculated as a sodicity indicator. Mean ESP was generally greater for slurry treatments than the control, with a trend of increasing ESP with application rate. This was particularly marked for cow slurry. At 0–5 cm depth ESP increased from 1.18 in the control to 1.75 at the highest rate of pig slurry and 5.60 at the highest rate of cow slurry. Similar trends were shown for CEC, exchangeable Na+ , K+ and Mg2+ , Ca2+ and Olsen P. The build-up of soil P due to slurry applications, together with this combination of physical and chemical factors, may increase the risk of P loss to surface waters, particularly from soils receiving high rates of cow slurry. 相似文献
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