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青海省生态环境治理面临的问题与草业科学的发展 总被引：9，自引：0，他引：9
青海省生态环境恶化的主要特征是：草地退化，水土流失，土地沙化，冰川湿地退缩，自然灾害频繁，人畜饮水困难，农村能源短缺。当前生态环境治理面临着试验示范不够、缺少治理规划、种苗供应混乱、资金投入不够等问题，需要加强治理规划工作和技术支撑体系、建立生态环境治理责任制、紧密结合生产结构调整及草产业的发展等方面开展工作。需要依据草业科学的原理，在生态环境治理中重视生态工程设计的应用，对治理区按照草地农业系统四个生产层次统筹考虑优化生产结构，发挥各系统和层次间的耦合效应。生态环境治理面临的问题为草业科学原理的实践及发展提供了广阔的天地。 相似文献
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且华敏 《养殖与饲料．饲料世界》2019,(1):120-121
就草地畜牧业的发展的情况,本文简述了草业发展机遇:畜牧业生产方式的转变,集约化、规模化专业牧场的兴建;指出了草业面临的挑战:草地生产力普遍比较低、牧草质量不高,牧草生产体系建设不够科学合理,存储和运输工作存在问题;提出了解决的方式:提高土壤肥力,建立科学的牧草生产体系,进一步做好草区基础设施建设工作。 相似文献
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柴达木盆地草地面积722.22万公顷,占土地总面积的27.68%,草地可利用面积512.52万公顷,占草地总面积和土地总面积的70.96%和19.64%.草地资源利用及草业生产中存在的问题是草地资源破坏严重,生态环境恶化;草地生产结构不合理,生产水平低;草地水利建设力度趋缓,重建轻管;草地基本建设投资少,重用轻养.应采取的对策是建立和完善草地农业系统,大力发展草地水利建设,加强草业生产技术推广,提高草业生产机械化水平,加快草地资源保护的法制建设,鼓励个人和企业投资草业生产. 相似文献
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我国草业工作面临的问题探讨 总被引：7，自引：2，他引：5
目前 ,草业已迅猛发展 ,方兴未艾。然而我国的草业水平与发达国家相比还存在着很大的差距。主要原因是对草业在国民经济中的地位认识程度不够 ,草业发展尚未得到足够的重视[1 ] 。为此 ,草业工作者还有责任和义务对草业工作做长期的、深入浅出的宣传。下面对草地的价值、生产建设中存在的问题及发展对策作一粗浅的探讨。1 草地的价值1 1生态效益 草地面积约占地球陆地面积的2 2 % ,约为林地的 5 0 % ,比农田大 1倍。广袤的草地作为地球生物圈的重要组成部分 ,是维护陆地生态环境的天然屏障 ,起着调节气候 ,涵养水源 ,防风固沙 ,保持水土 … 相似文献
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对中国草业发展战略的思考 总被引：1，自引：0，他引：1
本文分析了草原生态环境逐年加剧后,提出了中国草业应长期坚持生态治理、草地保护作为首要工作.并对今后的草业产业化,牧草及饲料作物育种及良种繁育应采取的措施进行了粗浅的分析. 相似文献
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草业科学框架纲要 总被引：28，自引：5，他引：23
草业科学是研究草地农业生态系统的科学,主要研究对象是3个要素群,3 个主要界面和 4 个生产层.草地农业生态系统的生物因子群居于核心地位,非生物因子群是生态系统的自然立地条件,社会因子群是草地农业系统所处的社会立地条件,草业科学需要分别设立相应的基础课,以探讨各个因子的基本内容及其相互关系,掌握基本理论和方法.草业科学最重要的3个界面是草丛-地境界面、草地-家畜界面、草畜-社会界面,它们是系统最活跃、最敏感、功能最密集的部分,是草业科学新的分支学科的生长点,草业学科针对3个界面及其功能的特异性和必要性设立专业基础课,而且针对生产需要,对基础课和专业基础课加以综合,开设专业课.3个界面,连缀了草业生产前植物、植物、动物和外生物4个生产层,根据社会生产的要求,草业科学按照4个生产层可将相关课程重组成二级专业,或沿着生产流程,按照有关学科的内在联系,重组成二级学科. 相似文献
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面向新世纪的草地生态学研究 总被引：1，自引：0，他引：1
在我国,草、草地、草业正引起人们极大的关注。这主要是因为我国面临着的诸多严重生态环境问题都与之有关,同时,草业发展还与国民经济发展中的诸多问题有紧密联系。草地生态学研究也面临着新的挑战与机遇。 相似文献
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柴达木盆地草地面积722.22万公顷,占土地总面积的27.68％,草地可利用面积512.527万公顷,占草地总面积和土地总面积的70.96％和19.64％。草地资源利用及草业生产中存在的问题是草地资源破坏严重,生态环境恶化;草地生产结构不合理,生产水平低;草地水利建设力度趋缓,重建轻管;草地基本建设投资少,重用轻养。应采取的对策是:建立和完善草地农业系统,大力发展草地水利建设,加强草业生产技术推广,提高草业生产机械化水平,加快草地资源保护的法制建设,鼓励个人和企业投资草业生产。 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。 相似文献
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本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。 相似文献
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REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air. 相似文献
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Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF
Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo. 相似文献
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以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。 相似文献