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本文在简析我国生猪产业发展现状的基础上,重点分析了我国生猪产业链各个环节的变化趋势,并对未来生猪产业的发展进行了展望。改革开放以来,我国养猪业产值占畜牧业产值的比重始终保持在50%左右,猪肉产量占全国肉类总产量的比重一直在60%以上。采用三元杂种猪的比例和进口种猪数量呈扩大趋势,生猪养殖现已形成相对独立与完善的产业体系,并向规模化、标准化、产业化、优势区域化、所有制多元化的方向发展,生猪生产力与生产效益也在不断提升。在可预见的未来,其他肉类仍无法在中国取代猪肉的位置,猪肉需求仍呈刚性增长趋势,但猪肉消费市场将呈现多样化的发展态势,也将促进猪的品种与利用的多样化。 相似文献
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我国是最大的猪肉生产国,生猪养殖业是我国农业生产中的支柱产业之一,猪肉在城乡居民肉类食品消费中占据重要地位。本文基于Malmquist指数和超效率SBM模型,依据2011—2021年26省份的生猪生产数据,对大规模生猪养殖的生产效率和全要素生产率及其时空差异特征进行评价分析。结果表明:从生产效率和全要素生产率综合来看,10年间我国大规模生猪养殖的生产效率呈现波动上升态势,生猪养殖技术效率年均值为0.812。从全要素生产率来看,全要素生产率年均增长率为0.5%,呈现周期波动趋势,主要依赖效率变化的增长(1.3%),生猪全要素生产率具有明显的区域性差异,中西部地区适合发展规模化生猪养殖,而东部沿海不太适合大规模生猪养殖。未来中西部应不断完善基础设施并加强技术引进与创新,在东部地区发展小规模生猪养殖,优化生产要素与资源的合理配置,调整养殖结构。 相似文献
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我国生猪规模化养殖及区域布局变化趋势 总被引：17，自引：0，他引：17
本文对我国生猪生产、生猪规模化养殖进程以及区域布局特点和变化趋势进行了分析。认为,随着我国养猪业规模化进程的加快,生猪养殖区域将在传统主产区保持平稳发展的基础上,向黄淮流域玉米、小麦主产区、东北粮食主产区转移以及其他边远地区生猪养殖将在未来几年得到快速发展,经济发达地区养猪业将向山区、周边地区转移。 相似文献
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中国沼气工程发展现状与展望 总被引：2，自引：0，他引：2
中国的养殖业发展迅速,对农村经济的发展起到了非常大的作用,中国肉类总产量达到了世界第一,畜牧业标准化和规模化养殖水平也不断提高,生猪规模化养殖比例已经达到了61%,蛋鸡规模化养殖比例达到了79%,奶牛达到了42%.虽然规模化养殖比例很高,但散养还是占了很大比重. 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