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71.
The suitability of some blood gas and biochemical parameters as diagnostic tools or early indicators of ascites syndrome in broiler sire lines 下载免费PDF全文
K. Hasanpur M. R. Nassiri G. Hosseini Salekdeh R. Vaez Torshizi A. Pakdel H. Kermanshahi M. Naghous 《Journal of animal physiology and animal nutrition》2016,100(3):456-463
In recent few years, there have been some attempts to find a reliable indicator trait as a selection criterion against susceptibility to ascites syndrome (AS). Blood parameters were of great interest as they could be measured in live animals without implementing an ascites‐inducing challenge (AIC). In this work, the suitability of some blood parameters was evaluated for diagnosing AS‐susceptible chicks in later steps of the disease in trial 1 as well as their early predictive ability in trial 2. In the first trial, one hundred 1‐day‐old chicks from two pure broiler lines namely S1 and S2 and, in the second trial, 226 1‐day‐old chicks from line S2 were subjected to AIC. Saline drinking water (1200 mg/l) and lower‐than‐standard ambient temperatures were the implemented AICs in trials 1 and 2 respectively. The blood parameters including pH, partial pressure of O2 (pO2), partial pressure of CO2 (pCO2), bicarbonate ion concentration (BIC), percentage of haematocrit (HCT) and saturated haemoglobin (SaO2) were measured twice per each bird at days 28 and 35 in trial 1 and once in trial 2 at day 21. The results of the first trial revealed that in line S2 some of the blood parameters differed significantly between the ascitic and non‐ascitic groups following exposure to AIC. In this line, the incidence of AS was accompanied by a lower pO2, SaO2 and BIC, while with higher pCO2 and HCT values. In the second trial, however, although almost all of the parameters showed meaningful differences between the ascitic and non‐ascitic broilers, only mean difference of BIC parameter was statistically significant. The general conclusion of this study is that the blood parameters can somewhat have diagnostic ability in the condition in which the AIC is already present, whereas the results did not approve their usefulness as early predictors of AS. 相似文献
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当网格剖分足够密时,采用差分解法可得到具有足够精度的有重土静力极限平衡数值解。根据大量计算分析,揭示了有效旁侧荷载宽度L、无量纲极限承载力 / 与内摩擦角 、无量纲参数λ的内在规律,据此将滑移线法数值解拟合为简洁的解析表达式,并在理论上证明了这一规律。通过与几种经典承载力公式的比较和分析,综合对该拟合公式的可靠度分析,论证了其正确性和可行性。 相似文献
74.
在人工气候室中,对盆栽条件下不同熟期的紧凑型与平展型玉米比较研究表明,单株玉米对土壤养分的反应株型间无规律性差异;不同熟期玉米间存在明显的规律性差异。植株苗期生长速率及高低土壤肥力下的差异与叶片N、K含量,光俣速率及不同光强,不同CO2浓度与的反应差异间存在明显的相关性。不同品种间苗期光合速率差异明显,土壤肥力高低对玉米苗期光合速率影响很大。 相似文献
75.
水稻闭颖授粉特性的遗传及其生物学意义 总被引:5,自引:0,他引:5
在正常条件下,水稻闭颖授粉特性是一种罕见的性状。已知具有这种特性的水稻品种有兴除1号和小麦稻。遗传分析表明,闭颖授粉受一对隐性核基因控制。试验结果表明,开花期遇到低温或连续降雨时,这种特性有利于水稻受精结实。此外还可看到,闭颖授粉特性能防止异花授粉,对保持种性有重要的生物学意义。 相似文献
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In this paper, the historical reasons of formation of the village inside the city are analyzed. It is indicated that such situation for the villages inside the city are the result of joint action of both the villagers and the government. The foundation of villages inside the city laid on the simple compensation for farmers in confiscating the rural land and lack of intelligence aids. In this paper, the ideas and measures for their reconstruction are put forward based on consideration of the reasons of their formation and difficulties in the reconstruction. 相似文献
78.
You lihua Wu Huibi Sun Renbo Wang Daivu 《保鲜与加工》1992,(4):48-53
The basic equations of wall plates of MAN' S dry gas holders are derived in this paper. According to the law of cylindrical bending given by the finite element results .we derive some approximate formula calculating the deflection and stresses of the wall plates from the basic equations. Compared with the known approximate calculating method.the method car. obviously increase the percision. 相似文献
79.
Mathematical model of power frequency electric field is established based on Charge Simulation Method(CSM) to analyze power frequency electric field caused by EHV lines with overhead ground wires and its effect, which are entering the megalopolis. Calculative method on the electric field under the transmission lines is analyzed and validated. According to the criterion of environmental evaluation, the distributing characteristic of electric field is summarized, in case of various arrangement manners of lines. At last, some advice and methods of eliminating electric field under the transmission lines entering the megalopolis is proposed with regard to protecting environment. 相似文献
80.
WANG Xue-song 《保鲜与加工》2003,(6):5-9
As a renovation envelope, double-skin facade has the characteristics of environmental function and unique aesthetic effect. In this paper, the composition and functional characteristics of double skin facade is introduced briefly, its development history and a detailed typologic analysis combined with typical cases is reviewed. It is pointed out that the double skin facade has a bright future in 21~(st) century and the function and aesthetics are the footstone for its typologic research. 相似文献