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我国南方草地资源现状及其发展前景 总被引:2,自引:0,他引:2
根据我国南方地区自然资源特点、草地类型、利用现状等,总结、分析了南方草地资源的优势、发展潜力和目前所面临的实际问题,并有针对性地提出了不同类型草地资源草产业发展模式。 相似文献
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我国有47亿亩草原、13亿亩草山草坡。为了充分挖掘草地资源潜力,提高草地畜牧业生产经济效益。我们对建立南方草地畜牧业经营模式进行了初步研究。我国南方草山草坡分布在13个省区,因地理位置和资源条件不同,形成了四种草地类型,即亚热带丘陵伏秋旱草地、亚热带高 相似文献
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根据中国南方草地资源的首次统一调查结果,阐述了中国南方14个省、区草地资源的数量、质量、自然特征及分布。分析了其利用现状及近10年来国家开发南方亚热带山地草地试验取得的显著经济效益、社会效益及生态效益。在此基础上,论述了开发南方草地资源的重要意义和必要性。 相似文献
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我国南方草地资源开发利用模式的探讨 总被引:9,自引:3,他引:6
我国南方草地资源十分丰富,但利用率却很低。通过综合分析南方草地资源现状、优势和问题,提出了南方草地利用的持续发展战略,发展方向和主要生产经营模式以及南方草地生产效率的评价体系。 相似文献
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《中国畜牧兽医文摘》2016,(11)
<正>南方暖温性草地,系指分布于我国南方地区的海拔约在800~3100m范围内的低中山至亚高山带的温凉湿润草地,是南方集中连片草地的主体。由于传统习惯和人口分布等方面的原因,目前该类草地的开发利用程度还相对较低,但从其水、热、土壤条件以及自然生物量看,该类草地是深具开发潜力的宝贵草地资源;从其气候特点及适宜建植的草地植被类型看,该类草地也是在我国南方地区牧养荷斯坦奶牛的难得的佳所。湖南城步南山牧 相似文献
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中国南方人工草地畜牧业回顾与思考 总被引:11,自引:0,他引:11
回顾和总结了我国南方20多年来人工草地畜牧业取得的科研成果与实践经验,分析了南方草地资源和人工草地的地位、特点、存在问题,提出南方草地畜牧业可持续发展的战略对策。 相似文献
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中国南方草地的开发及生产潜力分析 总被引:14,自引:0,他引:14
苏大学 《国外畜牧学(草原与牧草)》1998,(3):15-19
根据中国南方草地资源的首次统一调查结果,阐述了中国南方14个省,区草地资源的数量,质量,自然特征及分布,分析了其利用现状及近10年来国家开发南方亚热带山地草地试验取得的显著经济效益,社会效益及生态效益。在此基础上,论述了开发南方草地资源的重要意义和必要性。 相似文献
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基于MODIS的南方草地NPP遥感估算与应用 总被引:1,自引:0,他引:1
草地NPP遥感模型的构建是实现大面积草地NPP估算的有效途径之一。以MODIS-NDVI数据为基础,以南方草山草坡为研究对象,结合野外实测数据,分析了草地NPP与NDVI之间的关系,同时构建了以NDVI为自变量以及水热条件为调节因子的南方草地NPP遥感估算模型,并通过不同年份独立的实测数据对模型进行了验证。结果表明,南方草地NPP与NDVI之间存在5种相关类型,均达到了极显著水平。NPP的模拟值和实测值之间具有很好的相关性和一致性,5种草地类型R2分别为0.902 2,0.826 6,0.871 2,0.887 7和0.875 5,均达到了极显著水平,均方根误差(RMSE)和相对均方根差(RRMSE)均较小。表明模型的模拟结果比较可靠,为南方草地NPP估算及草地资源管理提供了一种有效的方法。 相似文献
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南方草地资源保护与开发的战略选择 总被引:6,自引:0,他引:6
长期以来,我国在南方草地资源的开发利用方面做了大量有益的探索,取得了不少成功经验。但总的来看,南方草地开发仍然处于较低水平。加快南方草地资源保护与开发,大力发展草产业,是新时期我国必须做出的重要战略选择。 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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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
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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