锡林郭勒典型草原植物多样性和蝗虫种群的关系

通过对锡林郭勒典型草原4种群落（羊草＋糙隐子草、大针茅＋羊草、克氏针茅＋冷蒿、克氏针茅＋糙隐子草）的物种丰富度指数、物种多样性指数、生态优势度指数和均匀度指数进行比较分析,对各种指数与蝗虫群落关系进行了研究。结果表明：羊草＋糙隐子草和克氏针茅＋糙隐子草群落的丰富度指数和多样性指数低于大针茅＋羊草群落,但高于克氏针茅＋冷蒿群落,优势度指数高于大针茅＋羊草,均匀度指数低于克氏针茅＋冷蒿群落;克氏针茅＋冷蒿群落的物种丰富度指数和物种多样性指数最低,生态优势度指数较高,群落均匀度指数高于其他3种群落;大针茅＋羊草群落的物种丰富度指数、物种多样性指数最高,优势度指数最低。相关分析表明,蝗虫种类数与均匀度指数极显著相关,蝗虫个体数与物种多样性指数显著相关。     

过度放牧对羊草杂类草群落种的构成和现存生物量的影响

主要分析了典型草原区的羊草Leymus chinensis杂类草草甸草原的土壤及植物群落随放牧强度梯度的变化,结果表明,随放牧压力的增大,表层土壤密度显著性增加,而表层土壤水分变化不明显。重度放牧区地上现存生物量高于中度放牧区,低于轻度放牧区。轻度放牧区的现存生物量与中度放牧区和重度放牧区,存在极显著性差异（P＜0.01）。其演替序列为：羊草草原+杂类草→羊草+糙隐子草Cleistogenes squarrosa+寸草苔Carex duriuscula→糙隐子草+大针茅Stipa grandis+米氏冰草Agropyron michhnoi→糙隐子草+星毛委陵菜Potentilla acaulis+冷蒿Artemisia frigida。因此,退化草原的植物组成取决于利用方式和强度,同时受生境条件的制约。其典型草原区的羊草杂类草草甸草原的演替序列介于典型草原与草甸草原两者之间。     

华北农牧交错带不同放牧强度绵羊食性研究

为探讨华北农牧交错带放牧绵羊的食性与草原退化的关系,本文以河北省张家口市塞北管理区典型草原为研究对象,于2016年7-8月运用饱和链烷技术研究羊草群落不同放牧强度下绵羊食性变化。结果表明:随牧压的增大,群落中羊草(Leymus chinensis)、花苜蓿(Medicago ruthenica)和野韭(Allium ramosum)的数量减少,克氏针茅(Stipa krylovii)、冷蒿(Artemisia frigida)和马蔺(Iris ensata)的比例增加;绵羊采食的牧草种类和比例各存在一定的差异,但绵羊优先采食羊草、野韭和花苜蓿,其次为糙隐子草(Cleistogenes squarrosa)和冷蒿,绵羊不喜食克氏针茅和阿尔泰狗娃花(Heteropappus altaicus),拒食马蔺。因此,重度放牧改变了羊草群落的植被组成,优质牧草减少,群落演替为冷蒿、克氏针茅和杂类草群落,从而导致了草地的退化。     

放牧强度对羊草草甸草原菌根效应的影响

以西乌珠穆沁旗羊草草甸草原为研究对象,研究了不同放牧强度对羊草草甸草原菌根效应的影响。结果表明:羊草地上生物量菌根效应在中度放牧区最高,群落地上生物量菌根效应在轻度放牧区最高;羊草与贝加尔针茅重要值菌根效应在中度放牧区最高,糙隐子草和寸草苔重要值菌根效应在不放牧区最高;Shannon-Wiener多样性指数和Margarlef丰富度指数菌根效应在不放牧区和中度放牧区高于轻度和重度放牧区。Simpson多样性指数和Pielou均匀度指数菌根效应在不放牧区和重度放牧区高于轻度和中度放牧区。     

松嫩平原主要草地群落放牧退化演替阶段的划分

本文采用聚类分析和主分量分析的方法对松嫩平原主要草地群落；贝加尔针茅－羊草群落，贝加尔针茅群落，贝加尔针茅－线叶菊群落、羊草群落和羊草－杂类草群落和羊草－杂类草群落的放牧经演替阶段进行划分，结果表明，每个群落的放牧退化演替过程的可划分为四个阶段，即：轻牧、中牧、重牧和过牧。随着放牧压梯度的变化，群落主要植物种的优势地位明显的替代变化，这与其生态生物学特性和动物的采集行为密切相关。     

退化羊草草原围栏封育多样性动态研究

在内蒙古锡林郭勒盟中国科学院内蒙古草原生态系统定位研究站对退化羊草草原围栏封育后的多样性动态进行了研究.样地于1983年围栏封育自然恢复,用封前植被为羊草草原的退化变体,即以冷蒿为建群种的含小叶锦鸡儿斑块的冷蒿+丛生小禾草、羊草群落.对25年恢复过程的群落多样性进行研究的结果表明:退化草原围栏封育自然恢复过程中,密度多度和生物量多度分布基本符合正态分布;植物群落的多样性指数和均匀性指数总体上保持稳定;羊草、冰草、冷蒿的生物量和密度的变化与多样性指数有显著负相关关系,星毛委陵菜的生物量和密度变化与多样性指数有显著的正相关关系.     

放牧对草甸草原植物群落结构及多样性的影响

在贝加尔针茅—羊草草甸草原的同一草地地境上,按放牧退化程度,将其划分为轻度退化区、中度退化区及重度退化区,并测定每一样地内植物群落特征及多样性指标。结果表明,随着放牧强度的增加,群落地上总生物量与中旱生植物的生物量变化保持一致,均呈降低趋势;中生植物先呈增加趋势,后下降;旱生植物呈增加趋势;群落优势种贝加尔针茅Stipa baicalensis和羊草Leymus chinensis呈降低趋势;物种丰富度指数先增加,而后降低;多样性指数和均匀度指数均呈增加趋势,优势度指数则相反。     

大针茅对放牧生态系统植物群落地上生物量的调控作用

通过放牧梯度试验,研究放牧对内蒙古典型草原5种优势植物在个体、种群和群落水平上的影响,探讨大针茅(Stip grandis)对放牧生态系统植物群落地上生物量的调控作用。结果表明:个体水平,中轻度放牧对以大针茅和糙隐子草(Cleistogenes squarrosa)为代表的丛生禾草株高影响较小,对以羊草(Leymus chinensis)、黄囊苔草(Carex korshinskyi)和米氏冰草(Agropyron michnoi)为代表的根茎型禾草株高影响较大,植物株高的降低与个体地上生物量减少呈显著正相关。种群水平,大针茅种群生物量对放牧的响应迟缓,羊草、米氏冰草、糙隐子草和黄囊苔草种群生物量的减少与多度减少呈显著正相关。群落水平,大针茅的耐牧性使其成为资源重配的获益者,轻中度放牧干扰下,其地上生物量的补偿生长缓冲了放牧对群落的影响,对维持群落生产力与功能稳定性起重要的调控作用。     

松嫩平原主要草原群落放牧干扰梯度对植物多样性的影响

松嫩草原五个主要群落类型放牧干扰梯度对植物样性影响的研究结果表明,在放牧过程通过牧畜的啃食、践踏作用干扰草原环境,使群落物种组成发生变化,优势地位发生更替,导致植物多样性变化。随着放牧干扰强度的增大,群落丰富度随之下降。多样性指标在中牧或重牧阶段出现峰值,主要缘于群落均匀度的增加。β多样性研究结果表明,羊草群落和羊草－杂类草群落植物多样性的耐牧性较差,而贝加尔针茅－羊草群落、贝加尔针茅－杂类草群落     

内蒙古典型草原地区5类植物群落叶面积指数的比较研究

应用直接测量与叶片面积-干重系数相结合的综合测定法,研究了内蒙古典型草原地区3类草原植物群落与2类沙地植物群落叶面积指数(LAI)的动态特征.结果表明,各类群落的LAI均随生育期后移而增高;最大值通常出现于8月份.5类群落比较,草原类型--大针茅、禾草、杂类草群落和羊草、丛生禾草群落,其群落、单子叶纲群和禾本科群的LAI均较高;退化草原类型--冷蒿、小禾草群落,不仅其群落LAI显著降低,而且双子叶纲群和菊科群LAI的比例明显增大.沙地群落类型--杂类草、小禾草群落和沙蒿群落的LAI较低,但双子叶纲群和菊科群相对比例较大.各群落的主要种群LAI在本群落中所占比例依次为沙蒿种群＞冷蒿种群＞羊草种群＞变蒿种群＞大针茅种群.     

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。     

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。     

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。     

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。     

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.