短穗兔耳草在不同海拔高度的生长特征研究

利用果洛州大武乡3700～4200m的海拔梯度,分别在海拔3700m、3800m、3900m、4000m、4100m对短穗兔耳草的生长特征进行了定株观测研究。研究结果显示:短穗兔耳草的匍匐茎数量和单位长度干重变化基本一致,即在海拔为3900m处达到最大值,低于或超过此海拔趋于减少,短穗兔耳草的匍匐茎长度随着海拔高度的升高而逐渐减少。     

短穗兔耳草的克隆生长特征

以调查统计的方法研究了高寒草甸匍匐茎植物短穗兔耳草Lagotis brachystachya无性系的生长特征、形态特征以及能量分配规律,研究结果表明:匍匐茎只有1条的短穗兔耳草最多,占60．47％,匍匐茎有4条的短穗兔耳草只占6．98％。在牧草生长盛期,短穗兔耳草无性系的基株高度4．03 cm,根长为9．11 cm,叶数为7．98;分株高度0．85 cm,根长2．73 cm,叶数为3．08;匍匐茎的茎生叶数为12．54,长度为15.14 cm,匍匐茎比节间重为2．18 mg／cm,粗度为0．97 mm,不同构件的干质量呈现出基株>匍匐茎>分株>茎生叶的规律。随着匍匐茎数目的增多,短穗兔耳萆无性系的基株根长逐渐增加,用于克隆繁殖的能量投资也有增加的趋势,其他参数都没有明显的变化规律。     

不同退化草地短穗兔耳草克隆生长及克隆繁殖特征

在不同退化草地（未退化、轻度退化、中度退化和重度退化）上对短穗兔耳草克隆生长及克隆繁殖特征进行了研究,结果显示：在中度退化草地上,短穗兔耳草的匍匐茎数量最多,单位长度的千重值也最大;短穗兔耳草的匍匐茎长度随着草地退化程度的加剧而逐渐减小,基株千重也随着草地退化程度的加剧而逐渐减小。     

短穗兔耳草克隆生长对高寒草甸土壤营养库衰退的响应

在退化高寒草甸土壤营养库变化背景下,对短穗兔耳草无性生长特性(基株和分株高度、根长和叶片数目,基株匍匐茎长度、粗度和茎生叶数目等)进行调查分析,结果表明:短穗兔耳草克隆生长特性随草地土壤养分资源丰富程度而变化,其觅食行为受环境异质性资源量影响明显。在不同土壤养分库含量样地,短穗兔耳草匍匐茎出现概率和匍匐茎粗度,以及基株匍匐茎上分株的高度、根长和叶片数依其基株匍匐茎数均不同;具不同匍匐茎数短穗兔耳草的基株高度、根长和叶片数变化亦不同。具2条或不具有匍匐茎的短穗兔耳草基株的高度,在土壤养分资源较为丰富的样地要明显小于养分比较缺乏的样地,土壤速效钾和速效氮与基株高度之间有一定的线性相关性。没有匍匐茎基株和分株根的根长度在土壤养分丰富的样地显著小于养分少的样地,而基株和分株叶片数在不同样地的变化无规律。两条中第一条和具一条匍匐茎上茎生叶片数在土壤丰富的样地大于土壤养分少的样地,但样地间匍匐茎粗度没有差异。相同土壤养分条件下,短穗兔耳草基株、分株以及匍匐茎等无性系生长特性无明显差异。短穗兔耳草克隆生长特征严格按其生境养分资源变化而变化,是一种环境异质性变化的适应性植物。     

不同退化草地上短穗兔耳草匍匐茎数量及长度的变化

在未退化、轻度退化、中度退化和重度退化草地上对短穗兔耳草无性生长及无性繁殖特征进行了研究，结果表明，在中度退化草地上短穗兔耳草的匍匐茎数量最多，其长度随着草地退化程度的加剧而逐渐变短。     

短穗兔耳草克隆生长与土壤养分的相关性分析

本研究选择未退化、轻度退化、中度退化、重度退化和极重度退化草地上的短穗兔耳草(Lagotis brachystachya)为研究对象,对短穗兔耳草克隆生长与土壤养分的相关性进行了研究,研究结果显示:PH值对短穗兔耳草匍匐茎数量的影响较为明显,而土壤的全氮、全磷、全钾对短穗兔耳草匍匐茎数量的影响不明显;土壤中全氮、全磷含量的高低对短穗兔耳草基株重的影响较为明显,而土壤的全钾含量和PH值对短穗兔耳草基株重量的影响不明显;土壤中全氮、全磷、全钾含量及PH值的高低对短穗兔耳草分株重的影响均不明显。     

不同氮磷组合对两种匍匐茎植物克隆繁殖特性的影响

研究了不同氮磷组合肥料水平下短穗兔耳草(Lagotis brachystachya)和鹅绒委陵菜(Potentilla an-serina)的生长和克隆繁殖特性.试验结果表明:短穗兔耳草的匍匐茎数、茎生叶数、匍匐茎长、分株叶片数、分株根长、分株高在各处理组之间差异均显著(P≤0.05),在处理组3水平下,各个生长指标的量最高;鹅绒委陵菜的分枝密度、平均分枝长度、间隔子长度、分株数、总生物量在各处理组之间差异均显著(P≤0.05);施入氮磷组合肥料对鹅绒委陵菜的根系膨大率和球根率也有显著影响,在处理组4水平下的量最高。     

不同氮磷组合对短穗兔儿草克隆繁殖特性的影响

以短穗兔耳草(Lagotis brachystachya)为研究对象,采用随机区组设计,观测了不同氮磷肥料组合对其生长和克隆繁殖特性的影响。结果表明:短穗兔耳草的匍匐茎数、茎生叶数、匍匐茎长、分株叶片数、分株根长、分株高在不同氮磷肥料组合间存在显著差异(P0.05),其中,处理的基株叶片数、匍匐茎数、茎生叶数及分株根长均达到最大值,分别为16.25片、7.23条、11.25片及4.32 cm;而对匍匐茎长无显著影响。因此,土壤氮磷肥力条件的差异对短穗兔儿草的克隆繁殖特性存在一定的可塑性。     

短穗兔耳草生物量分配格局对高寒草甸营养库衰退的响应

在青海省三江源腹地,选择由于草地利用方式不同而形成的3个具有不同养分资源与植物群落特征的高寒草地,进行了短穗兔耳草（Lagotis brachystachya）生物量在各无性系的分配特性研究,以了解其对土壤营养库衰退的响应方式。结果表明,土壤养分状况对短穗兔耳草生物量在不同无性系构件间的投资也有影响,在土壤养分资源较丰富样地,短穗兔耳草对基株根茎生物量的投资最大,而对基株和分株叶片生物量投资最小;相反的趋势出现在土壤养分贫瘠的样地;但在土样养分中等的条件下,短穗兔耳草对匍匐茎的生物量投资最大,而在养分资源较贫瘠或丰富的样地又趋于减小。短穗兔耳草生物量分配格局随生境养分资源变化而改变,这是克隆植物有效适应生境变化的重要生态对策之一。     

不同海拔高度短穗兔耳营养草生长的研究

青藏高原因其独特的自然条件,大量分布具有克隆生长特性的植物。多年来,对青藏高原高寒草甸地区植物种群克隆生长特性的研究报道较少,研究范围也只涉及一些根茎类无性系材料和少量匍匐茎类无性系材料,大规模的深入研究尚未展开。短穗兔耳草（Lagotis brachystachya）是高寒嵩草草甸地区典型的多年生匍匐茎植物,是高寒草甸的主要伴生种,具有很强的无性繁殖能力,     

癸氧喹酯干混悬剂含量测定的改进

采用高效液相色谱法测定癸氧喹酯干混悬剂的含量,在2-250μg/mL范围内,峰面积的常用对数与进样量浓度的常用对数呈良好的线性关系,R^2=1(n=5),平均回收率为99.24%~99.51%,RSD在0.05%~0.28%。此方法分析时间短,样品前处理简便、定量结果准确,重现性好,结果满意,为其质量控制提供了依据。     

猪毛色遗传的研究进展

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。     

商会自治的基石——商会自治规范研究

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。     

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.     

Mechanism of Action of Probiotic Function of Lactobacilli

乳酸杆菌作为益生菌广泛用于人和动物.本文综述了乳酸杆菌改善宿主健康的机制.乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道.文章重点讨论了乳酸杆菌表面成分(表面蛋白、脂磷壁酸和肽聚糖)与肠道受体(C型凝集素受体、Toll样受体和Nod样受体),阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制.     

中华人民共和国农业部公告 第267号

为贯彻落实《兽药生产质量管理规范》(简称《兽药GMP》),进一步推动兽药GMP实施进程,我部制定了《兽药生产质量管理规范检查验收办法》,现予公告。本公告自2003年6月1日起施行。附件:兽药生产质量管理规范检查验收办法二○○三年四月十日第一章 总则 第一条 为推动《兽药生产质量管理规范》(以下简称兽药GMP)的实施,规范兽药GMP检查验收工作,制定本办法。 第二条 农业部负责全国兽药GMP管理和检查验收工作;负责制修订兽药GMP检查验收管理规定;负责兽药GMP检查员队伍建设和监督管理工作,负责国际兽药贸易中GMP互认工作。 …     

鸡败血支原体垂直传播模式及其阻断方法

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。     

Comparison of 2 methods of centesis of the bursa of the biceps brachii tendon of horses

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.     

不同样本商品蜂蜜中硒含量的测定

用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10～0.82μg/g。表明:蜂蜜应视为天然富硒营养品。