刈割对羊茅黑麦草叶片组织转化的影响

利用测定叶片组织转化分析方法，研究了在营养期或繁殖期开始以２、６、１０和１４ｃｍ留茬刈割度高，对羊茅黑麦叶片发生，伸长，枯萎和死亡的影响。结果表明，在营养期以低茬刈割较为合理，可加快羊茅黑麦草叶片组织转化速率。     

羊茅黑麦草和无芒雀麦叶片再生动态及其与草地管理的关系

羊茅黑麦草和无芒雀麦刈割后叶片再生动态的试验结果表明，这两种禾草刈割后，不同再生期的叶伸长率，萎蔫率、净生长率及叶片发生率间存在着显著差异，刈割强度影响不显著，留茬高度在５ｃｍ与１０ｃｍ之间，上述各项参数相对稳定，叶片动态对草地管理有重要的实践意义，建议以叶片动态作为刈割和放牧的判断标准之一。     

刈割强度对多年生黑麦草和高羊茅再能力影响的研究

多年生黑麦草和高羊茅刈割后禾草群体再生动态的试验结果表明，在６种留茬高度之间一周干物质生长量无显著差异，两种草亦无显著差异，但９种不同刈割时间之间上述参数表现出显著差异，具有随刈割时间延长而降低的趋，多年生黑麦草的降低幅度大于高羊茅。据此。建议通过调节刈牧频率适当重刈和重牧，达到草地持续高效利用的目的。     

不同刈割方式对苇状羊茅混播草地生产性能的影响

采用不同刈割高度和不同留茬高度处理对优良混播组合“苇状羊茅 +多年生黑麦草 +扁穗雀麦+白三叶”人工草地进行了刈割利用试验 ,结果表明 :该混播组合人工草地刈割利用时以草层高度40cm、留茬高度 5cm效果最好 ,可最大限度地发挥该草的生产性能和延长利用期     

刈割对羊茅黑麦草叶片净生长和净牧草积累的影响

利用植物组织转化分析方法，研究羊茅黑麦草在不同刈割时期和留茬高度对叶片净生长和净牧草积累的影响。结果表明，低茬（2和6cm）刈割时叶片净生长动态呈“S”曲线型；而高茬（10和14cm）则割为抛物线型，但其第二茬则呈“S”曲线型。牧草净积累在各处理中均以“S”型曲线增长。对后初期叶片净生长率表现为高茬大于低茌，后期则相反。牧草净积累率在第一茬为低茬大于高茬，早期变化幅度大于晚期。在第二茬则相反。     

刈割对无芒雀麦和羊茅黑麦草生物量和蘖密度的影响

经两年的刈割对两种牧草生物量和蘖密度影响试验，结果表明，营养期和繁殖期开始不同刈割间羊茅黑麦草生物和蘖密度差异不显著，不同留茬高度间无芒雀麦地上干物质重和蘖密度差异不显著，羊茅黑麦草差异显著。     

高羊茅在不同刈割组合下生产能力的研究

高羊茅Festuca arundinacea能够很好地适应半干旱的气候和土壤条件,在一定程度上具有较强的耐刈割能力.然而,过度和频繁的刈割会导致牧草生产水平的严重下降.研究证明:在生长期内每隔30 d刈割1次,并且留茬在10 cm时最适宜高羊茅当年的饲草生产和以后几年的可持续利用.这种利用组合,不但有利于畜牧业的生产,而且有利于天然草地的建设与改良.     

刈割对羊茅黑麦草和无芒雀麦蘖转化的影响

根据种群生命统计分析原理，进行了刈割对羊茅轩麦草和无芒雀麦蘖转化的影响的研究。结果表明，羊茅黑草经元芒雀麦有较低的蘖死亡率和较高的蘖出现率，在营养期对刈 茅黑麦草优于繁殖期，应避免频繁强度利用元芒雀麦，羊茅黑草则适合频敏地强度与轻度结合刈牧。     

刈割对混播草地种群生长与产量关系及种间竞争特性的影响

研究了不同刈割次数和时间下,混播草地中多年生黑麦草产量与叶片生长、分蘖数间的关系,白三叶产量与匍匐茎生长、分枝数间的关系,以及两者种间竞争特性变化。结果表明：黑麦草产量随分蘖数(年刈割8次和4次例外)或叶片生长长度增加呈弱显著或显著增加趋势,白三叶年产量与匍匐茎分枝数呈显著正相关;高频刈割利于黑麦草和白三叶种群生长的正效应发挥,低频刈割和对照增强种间个体的竞争;两者生长点数、种群产量关系由高频刈割的显著正相关向低频刈割和对照的显著负相关转化。可见,随刈割频率的降低和刈割日期的推后,黑麦草和白三叶的种间竞争渐趋明显。     

留茬高度对黑麦草╋白三叶草地植物补偿性生长的影响

以我国南方广泛分布的黑麦草(Lolium perenne)+白三叶(Trifolium repens)退化草地为研究对象,探讨了不同留茬高度刈割处理下草地群落、功能群和主要优势物种补偿性生长的响应模式。研究表明,刈割能提高黑麦草+白三叶草地地上生物量,高茬(12 cm,HC)和低茬(6 cm,LC)刈割均能实现群落地上生物量正补偿性生长;禾草和杂类草在低茬和中茬(9 cm,MC)等较大刈割强度下仍能获得较高补偿性生长;豆科牧草地上生物量在高茬及中茬等适度刈割处理下为超补偿生长模式,补偿指数G/C分别为1.20和1.23,在低茬刈割下为低补偿模式(G/C=0.98)。表明豆科牧草的补偿性生长受刈割强度影响较大,在草地管理过程中可通过合适的留茬高度来提高豆科牧草的产量。而菊科类植物在3种留茬高度下均表现为G/C1(介于0.31~0.48),显示出明显的欠补偿特征。通过对不同留茬高度处理地上生物量与根系生物量分配关系分析发现,禾草类地上补偿性生长有可能是通过改变植株的生物量分配模式来实现的;杂类草和菊科植物则是由地上部分生长与根系协同生长完成;刈割对豆科植物的影响主要体现在地上部分,其根系生长具有相对独立性。群落和功能群水平的地上生物量补偿性生长最终都是由各优势物种不同响应模式来实现的。该研究结果对于解释放牧和刈割等利用方式对黑麦草+白三叶混播草地的种群结构变化、生物量构成和再生特性影响等具有一定的参考价值。     

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。     

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。     

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。     

乳酸杆菌益生作用机制的研究进展

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。     

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。 …