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长江上游退耕还林还草工程与西部开发已经开始实施,生产上急需大量优质高产牧草种子,目前牧草种子生产已成为本地区发展草地畜牧业的头等大事。在综合分析重庆市牧草种子业现状和存在问题的基础上,针对本地区生产实际,提出了牧草种子业发展措施与对策,且对本市未来牧草种子业进行了展望。这对于推动本地区草地畜牧业的发展和加快三峡库区生态环境建设无疑具有重大意义。 相似文献
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云南省牧草种子业的现状与前景 总被引:3,自引:1,他引:3
简述了云南省牧草种子生产现状。从自然环境、社会环境和市场前景等方面分析了云南省牧草种子业发展的利弊条件。在此基础上 ,对云南省牧草种子业发展需要重视的问题进行了讨论 相似文献
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简述了云南省牧草种子生产现状.从自然环境、社会环境和市场前景等方面分析了云南省牧草种子业发展的利弊条件.在此基础上,对云南省牧草种子业发展需要重视的问题进行了讨论. 相似文献
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牧草种子作为人工草地建设、退化草地改良以及植被恢复等牧草生产和生态环境改良的重要物质基础,牧草种子的质量状况是关系到草地建植和牧草生产成败的首要因素。通过对种子老化现象概述,分别从老化引起的各方面牧草种子生理变化进行了分析阐述。围绕化学药剂处理、渗透调节、超干处理、吸湿-回干处理等修复和提高牧草种子活力的研究进行比较分析。另外,根据牧草种子老化生理和修复研究的发展和现状,提出未来牧草种子活力与老化生理机制的研究趋势及发展方向。 相似文献
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牧草种子在草原植被恢复和草牧业生产中发挥着重要作用。中美都是国土辽阔的大国,本文通过对比近十年内中美2国牧草种子生产的相关数据,分析中美草种业在牧草种子生产规模、专业化生产的地域性、新品种选育、产业化与机械化以及生产技术研究上的差异。结果表明:尽管我国在牧草种子专业化生产的地域性方面取得了长足进步,但是种植面积和单产仍然低于美国,每年仍需进口大量牧草种子来满足生态建设和草产业发展的迫切需求;与美国相比,我国牧草种子生产在育种、产业化、机械化和专业化等方面存在巨大的潜力,而且我国牧草种子产业亟需培育大型龙头企业。基于中美在牧草种子生产体系上的差异,本文比较分析了中美两国在牧草种子生产方面的差异和我国的发展潜力,并提出了当前我国牧草种子产业发展需要集中努力的方向和建议,希望能为推动我国草种业快速健康发展提供参考。 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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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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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