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当前水产养殖效益影响因素及发展对策研究 总被引:2,自引:0,他引:2
我国是世界上唯一一个水产品养殖产量超过捕捞产量的国家,且养殖产量已占到世界养殖总产量的70%以上。统计数据显示,2005年我国的水产品总产量为5107.6万吨,其中养殖产量为3395万吨,占总产量的66.48%,养殖产量占有如此高的比重,这在世界主要渔业大国中是绝无仅有的。2008年1~5月全国水产品总产量为1557.2万吨,同比增长4.46%。水产养殖业的发展,一方面使水产品的供求关系发生了很大的变化;另一方面改善了产业结构,推动了整个渔业经济的发展。 相似文献
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一水产养殖业发展与贡献
2011年,中国渔业总产量为5603万吨,占世界渔业总产量的36%;中国水产养殖产量为4023万吨,占中国渔业总产量的72%,占世界渔业总产量的26%,占世界水产养殖产量的63%。中国是世界上唯一养殖产量超过捕捞产量的渔业大国。 相似文献
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近年来,全球水产养殖业得到迅速发展,其中我国的发展占有重要位置。据FAO资料,当前全球海、淡水水产养殖总产量高达4500多万吨,其中中国水产养殖产量为3200万吨左右,占全球水产养殖总产量的71%以上(FAO 2002)。我国水产养殖的养殖总产量占我国渔业总产量的60%以上。已成为世界上唯一一个养殖产量超过捕捞产量的国家。 相似文献
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党的十一届三中全会以来,我国水产业经历了改革开放、发展振兴的“黄金时代”,从1984年起,水产品产量连续突破600、700、800、900万吨,1988年达到1061万吨,首次突破千万吨大关,成为世界第三渔业大国。水产品产量的增长主要靠养殖业,1988年,全国海、淡水养殖产量532万吨,占水产品总产量的50.2%,养殖产量第一次超过捕捞产量。我国已成为世界水产养殖第一大国。 相似文献
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虾、蟹的营养学研究及饲料开发 总被引:1,自引:0,他引:1
1我国虾、蟹的养殖现状随着国民经济的高速发展和农业结构调整的深入,我国水产养殖业得到了迅猛的发展。其中以半精养和高密度精养(集约式养殖)为主要方式的水产养殖业,已有近20年的历史,从1988年起,我国水产养殖的产量首次超过捕捞产量,到2002年,我国水产养殖产量高达2906.89万t,占水产品总产量的63.68%,人均水产品占有量已达到36kg,超过世界平均水平(30kg)。水产品不仅为消费者提供了优质的动物蛋白源、满足人们对食品的多样化需求,而且是出口创汇的重要商品。2002年水产品出口量和出口额分别为208.5万t、46.9亿美元,水产品出口份额约占全… 相似文献
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正改革开放以来,水产养殖业同其他行业一样有着丰硕的成果,特别是1985年我国确立了"以养为主"的渔业发展方针,水产养殖业成绩斐然,我国是世界上唯一的水产养殖产量超过捕捞产量的国家,养殖产量占世界养殖总产量的70%。特别是静水土池塘养殖,我国的水平遥遥领先。2016年全国水产品产量6 900多万 t,其中养殖5 100多万 t。淡水养殖产量3 179万 t,占淡水产品产量的93%,鱼类产量2 815万t,淡水 相似文献
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再过4年,即将迎来21世纪,在这4年中,从我国的宜渔资源优势和市场潜力分析,以1993年为基数,到2000年将再增加1000万吨水产品来满足人民的需要,即使如此,我国水产品人均占有量仍然是低的,仅达当前世界人均水平。一、我国水产养殖的发展态势从1978──1993年,我国水产养殖产量以平均年递增14.6%的速度发展,1978年水产养殖总产量仅121.l万吨(其中海水养殖产量为44.9万吨,内陆养殖为76.2万吨),1993年水产养殖总产量达到956.9万吨,(其中海水养殖产量为308.7万吨,内陆养殖产量为648.2万吨),1994年水产品总产量已提前6年完成本… 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