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柞场内的柞树修剪形式与柞树生长发育、柞叶产量、叶质优劣、调节气候、防治病虫害、放养管理、人力节省等都有密切的关系。根据蚕儿生活阶段的气候环境及蚕儿生理需要来修剪柞树,是促使蚕儿发育健壮,柞树生长旺盛、保证柞茧丰收的主要关键之一。柞树的剪定形式在山东有中刈柞和根刈柞两种, 相似文献
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柞树是放养柞蚕的重要饲料,为了充分有效的利用柞树林型,提高柞蚕茧产量,笔者对柞林资源的林型进行了调查。结果表明,黑龙江省放养柞蚕主要树种是蒙古柞,而蒙古柞林所处的立地条件及生长特点可分为3种林型,其中胡枝子-蒙古柞林、榛子-蒙古柞林是最佳的放养柞蚕林型地。1蒙古柞1.1形态特征蒙古柞幼树树皮呈暗灰褐色,成熟树树皮呈暗灰色。幼期枝条呈紫褐色,小枝呈栗褐色,枝有棱,枝表面无毛。叶子常集生于枝条顶端,叶柄略短;叶呈倒卵形和倒卵长形,叶尖呈钝形,叶幅前端较为宽大(4￣9cm),叶长度为5￣20cm;叶子侧脉7￣12对;叶表面呈绿色,叶背颜色… 相似文献
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目前,中共中央、国务院办公厅发布了《粮食节约行动方案》,要求饲料粮减量代替,寻求新型饲料成为当下畜牧业发展的需求。柞树在我国广泛分布,柞叶产量大,可以作为畜禽饲料进行利用。本文对柞树资源化利用现状及前景进行综述,以期为深入研究提供参考。一、柞树简介柞树是壳斗科栎属经济植物的总称,又名栎树、橡树,抗寒耐旱、生命力强,在我国广泛分布。从海南到黑龙江都有柞林,在黑龙江五大连池市有柞林21.7万亩。据有关数据,每年用作放养柞蚕的不到6%。 相似文献
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柞树枝干害虫有的蛀食柞树枝干及根部,有的吮吸柞叶或嫩枝汁液,严重影响柞树的正常发育,降低柞叶的质量和产量,影响柞蚕生产。橡实害虫主要危害柞树橡实,使被危害的橡实不能发芽。下面介绍柞树主要的枝干害虫与橡实害虫及其防治方法。 相似文献
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“高美施”是一种高效的农作物腐殖酸有机液肥，富含有氮、磷、钾等多种元素，将其用于对柞树叶面喷施，可以有效解决柞叶老化快、火芽产叶量偏低等问题，提高柞叶产量及质量，从而提高柞蚕茧产量和质量。 相似文献
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<正> 柞蚕以柞叶为食,故柞场是放蚕的基础。山东省一些蚕区历来的习惯是春蚕用老柞(二年生柞),秋蚕用芽柞(一年生柞)。但因春季干旱少雨,柞树叶质衰老硬化快,蚕、柞不相适应。如何改造老柞,使之符合蚕儿生长发育的要求,这历来是春蚕饲料调节需要探索的问题。曾采用三眠柞、二芽柞和老眠柞等修剪形式,来控制春蚕用柞的老嫩和含水量的高低,对调节春蚕饲料起到一定的作用。但是这几种修剪形式都是用截短枝条的方法(只是位置轻重不同),更替顶芽生长,推迟发芽期,其结果缩小了树冠,影响了光能的充分利用,对柞树长势挫 相似文献
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为了探索辽东山区柞园生态系统物质循环规律，选择3个标准柞园内3枝龄的辽东栎、蒙古栎、麻栎、槲树，对柞园生态系统内柞树、草本植物、灌木植物等的N、P、K物质含量进行了测定，研究柞园生态系统的物质投入、贮存、归还、输出状况，并据此建立了柞园物质流动模型。结果显示：柞园每年贮存的物质总量，N、P和K分别为118.56 kg/hm2、8.98 kg/hm2和62.64 kg/hm2;其中N的贮存量为柞树63.43%,草灌植物36.57%;P的贮存量为柞树75.81%,草灌植物24.19%;K的贮存量为柞树68.22%,草灌植物31.78%。柞园生态系统归还物中柞树的枯枝落叶N归还量为9.34 kg/hm2,P归还量为0.75 kg/hm2,K归还量为2.97 kg/hm2;草灌植物的枯枝落叶中N归还量为2.79 kg/hm2,P归还量为0.16 kg/hm2,K归还量为1.56 kg/hm2;柞蚕粪... 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