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991.
Phenotype and forage value, including conservation properties, of grasses The phenotype of grasses can be influenced by the date of harvest as well as by breeding programs. In contrast to dicotyledons, the stems of grasses are younger than the leaves, although the grass leaves are usually considered to have a higher nutritional value than the stems. In a field experiment, Lolium multiflorum Lam. ssp. gaudini (Parl.) Schinz et Kell. was grown as a model-plant in order to study effects of ploidy-level, N-fertilization, stage of development, and growth time on the main aspects of nutritional value and conservation properties in relation to the phenotype. As regards the nutritional value, the interactions of ploidy × plant organ (=stem or leaf) and of ploidy × N-input were not significant. Hence, the results for leaf and stem can be generahzed. Until the emergence of the inflorescence, EC 49, the stem showed a significant higher net energy content than the leaf; at later stages of development this relationship changed. The evaluation of the net energy content of leaf and stem was significantly influenced by the method of estimation. In vitro methods with rumen liquor may show the best approximation to the real value. The crude protein/energy ratio of the stem as compared to the leaf better meets the nutritional requirements of ruminants; on the other hand the leaf was more valuable than the stem in relation to the nitrate content, especially when the whole plant showed an increased nitrate level. The general relationship between the mineral content and the phenotype was not evident. The investigation indicated significant differences between stem and leaf in relation to their conservation properties. The leaf showed more favourable drying properties than the stem but ensilability was better for the stem than for the leaf. As a result of this investigation it is assumed that, in the past, the nutritional value of young stem has been underestimated whereas the value of the leaf has been overemphasized. This may also be due to the criteria and determination methods of the nutritional value. 相似文献
992.
A. O. Refsdal 《Acta veterinaria Scandinavica》1976,17(2):190
Non-return rates at different stages after insemination were compared in daughters (n = 21,212) of five translocation heterozygous sires with all cows and heifers (n = 610,714) represented in the Norwegian Red Cattle (NRF) breeding statistics during the period October 1970 to September 1972. The daughters of the carrier bulls showed statistically significant lower non-return rates for 0–30, 30–60, 60–90, 90–120, 120–150, 150–180 and 180–270 days as compared with the control animals. The decline in non-return percentage for the daughters of translocation sires was greater than in the control animals during the period from 0–30 to 60–90 days indicating higher losses of fetuses during the early period after insemination.Daughter groups of carrier bulls consisting of adult cows only showed higher non-return rates than groups comprising both cows and heifers. 相似文献
993.
区域经济中博弈论在节水灌溉中的应用研究 总被引:2,自引:0,他引:2
当今水资源短缺,区域经济中节水具有重要意义,为了推广节水灌溉,有利于区域经济的发展,本文建立了督导推广节水灌溉博弈模型,从而得出有益的结论。 相似文献
994.
吴金明 《湖南农业大学学报(自然科学版)》1993,(2)
运用系统学原理剖析了农村经济系统中农村社会化服务子系统的结构、功能、需求与供给,在揭示并分析我国农村在建立社会化服务体系实践中存在的矛盾与困惑的基础上,提出构成以乡镇经济联合社为依托,以农科教结合为核心内容的农村社会化服务体系的新观念与对策. 相似文献
995.
分4批从孵出的海波罗鸡雏中选出888只公母混合雏,每批222只,研究几内亚热带气候对海波罗肉仔鸡生长期耗料量的影响。结果表明,4批鸡的整个试验中的累计耗料量分别为4745.58g/只、4507.44g/只、4682.73g/只和4545.77g/只。第Ⅱ、Ⅲ和Ⅳ批鸡的累计耗料量比第Ⅰ批鸡分别少5.28%、1.13%和4.40%,第Ⅱ和第Ⅳ批累计耗料量比第Ⅲ批分别少4.11%和3.23%,第Ⅱ批累计耗料量比第Ⅳ批的少0.5%,比第Ⅰ、Ⅲ和Ⅳ批偏少。4批鸡4周龄料肉比分别为1.23、2.03、1.90和1.67,饲料报酬都高,7周龄分别为3.78、2.97、2.56和2.52,除第Ⅰ批外,各批7周龄饲料报酬较高。在整个试验期,4批鸡1-7周龄的平均累计耗料量为4622.88g/只,其平均累计料肉比为2.28g,累计耗料量比海波罗的标准少217.12g,即4.70%。由于几内亚热带气候影响,本试验鸡采食量少,料肉比较低。 相似文献
996.
The mechanism of electrochemical reduction for species Cu(I)-EDTA in eiectroless copper plating was studied by means of polarization curve,rotating disc electrode,chrono-potentiometry and chronocoulometry.The result of reaction order determination indicat 相似文献
997.
It is difficult to control the noise of punch press. In this paper, using experiment way, the mechanism of noise generation on JB2360 type punch press which is widely used in works is investigated. According to experiment results,a method for reducing pun 相似文献
998.
陆发兴 《湖南农业大学学报(自然科学版)》1991,18(1)
In this paper, a method of vector chinese character font definition and vector chinese character font library organization is discussed in detail. The paper also describes a commonly used CCP technique for CAD systems in personal computers and working sta 相似文献
999.
In this paper, with observing a great deal of experimental results, the kinetics laws of the transformatins of the carbides for the medium-Mn Steels at the intercritical heat treatment have been studied and analysed, and the hypothesis of the grained mech 相似文献
1000.