放牧家畜对东祁连山高寒灌丛草地枯落物层及水文功能的影响

为探究放牧不同家畜对高寒灌丛草地枯落物层和土壤层的水文影响,于2020年7月–8月在东祁连山天祝高寒地区对放牧甘肃马鹿(Cervus elaphus kansuensis)和混牧牦牛(Bos grunniens)与藏羊(Ovis aries)的灌丛草地枯落物层和土壤层的持水性、持水速率、拦蓄量等特性进行了研究。结果表明,枯落物总厚度表现为混牧牦牛与藏羊样地(3.53 cm)放牧甘肃马鹿样地(2.83 cm),枯落物总储量表现为混牧牦牛与藏羊样地(219.45 g·m~(-2))放牧甘肃马鹿样地(92.86 g·m~(-2))(P 0.05);混牧牦牛与藏羊样地的枯落物平均持水量和初始持水速率均大于放牧甘肃马鹿样地;枯落物平均最大持水量表现为混牧牦牛与藏羊样地(20.78 t·hm~(-2))放牧甘肃马鹿样地(10.71 t·hm~(-2)),平均最大持水率表现为混牧牦牛与藏羊样地(221.00%)放牧甘肃马鹿样地(148.11%),平均最大拦蓄量表现为混牧牦牛与藏羊样地(939.21 t·hm~(-2))放牧甘肃马鹿样地(348.58 t·hm~(-2)),以及有效拦蓄量表现为混牧牦牛与藏羊样地(627.52 t·hm~(-2))放牧甘肃马鹿样地(187.90t·hm~(-2))(P 0.05)。放牧甘肃马鹿样地灌丛间和灌丛内的浅层(0-40 cm)土壤含水率均显著高于混牧牦牛与藏羊样地,深层(40-100 cm)土壤相反;灌丛间0–30 cm土层容重表现为混牧牦牛与藏羊样地放牧甘肃马鹿样地,灌丛内则相反;土壤初渗速率表现为放牧甘肃马鹿样地(10.98 mm·min~(-1))混牧牦牛与藏羊样地(6.92 mm·min~(-1)),稳渗速率同样表现为放牧甘肃马鹿样地(7.12 mm·min~(-1))混牧牦牛与藏羊样地(5.90 mm·min~(-1))。综上所述,与单牧马鹿相比,混牧牦牛与藏羊更有利于高寒灌丛草地水源涵养和水土保持功能的发挥。     

放牧家畜对东祁连山高寒灌丛草地枯落物层及水文功能的影响

为探究放牧不同家畜对高寒灌丛草地枯落物层和土壤层的水文影响,于2020年7月 –8月在东祁连山天祝高寒地区对放牧甘肃马鹿(Cervus elaphus kansuensis)和混牧牦牛(Bos grunniens)与藏羊(Ovis aries)的灌丛草地枯落物层和土壤层的持水性、持水速率、拦蓄量等特性进行了研究.结果表明,枯落物总厚度表现为混牧牦牛与藏羊样地(3.53 cm)>放牧甘肃马鹿样地(2.83 cm),枯落物总储量表现为混牧牦牛与藏羊样地(219.45 g·m?2)>放牧甘肃马鹿样地(92.86 g·m?2)(P<0.05);混牧牦牛与藏羊样地的枯落物平均持水量和初始持水速率均大于放牧甘肃马鹿样地;枯落物平均最大持水量表现为混牧牦牛与藏羊样地(20.78 t·hm?2)>放牧甘肃马鹿样地(10.71 t·hm?2),平均最大持水率表现为混牧牦牛与藏羊样地(221.00％)>放牧甘肃马鹿样地(148.11％),平均最大拦蓄量表现为混牧牦牛与藏羊样地(939.21 t·hm?2)>放牧甘肃马鹿样地(348.58 t·hm?2),以及有效拦蓄量表现为混牧牦牛与藏羊样地(627.52 t·hm?2)>放牧甘肃马鹿样地(187.90 t·hm?2)(P<0.05).放牧甘肃马鹿样地灌丛间和灌丛内的浅层(0?40 cm)土壤含水率均显著高于混牧牦牛与藏羊样地,深层(40?100 cm)土壤相反;灌丛间0–30 cm土层容重表现为混牧牦牛与藏羊样地>放牧甘肃马鹿样地,灌丛内则相反;土壤初渗速率表现为放牧甘肃马鹿样地(10.98 mm·min?1)>混牧牦牛与藏羊样地(6.92 mm·min?1),稳渗速率同样表现为放牧甘肃马鹿样地(7.12 mm·min?1)>混牧牦牛与藏羊样地(5.90 mm·min?1).综上所述,与单牧马鹿相比,混牧牦牛与藏羊更有利于高寒灌丛草地水源涵养和水土保持功能的发挥.     

牦牛和藏羊混合放牧对放牧家畜采食量和植物补偿性生长的影响

为探究放牧方式对青藏高原高寒草地家畜的采食量和植物补偿生长的影响,本试验在环青海湖流域高寒草地设置放牧方式（牦牛单独放牧、藏羊单独放牧、牦牛和藏羊1：2混牧、牦牛和藏羊1：4混牧、牦牛和藏羊1：6混牧）控制试验,以期确定草地的承载力,并为制定合理的草地管理措施提供依据。试验结果表明：在群落水平上,家畜的采食量在藏羊（Ovis aries）单独放牧以及牦牛（Bos grunniens）与藏羊1：2混牧方式下,显著高于其他方式（P<0.05）;在功能群水平上,藏羊单独放牧与牦牛和藏羊1：2混牧这2种放牧方式下家畜对豆科植物的采食量较高;藏羊单独放牧与牦牛和藏羊1：2混牧植物的补偿生长能力显著高于其他放牧方式（P<0.05）。研究表明：藏羊单独放牧时,其采食量最高;牦牛和藏羊1：2混牧的放牧方式对植物补偿性生长的促进作用最明显。因此,从放牧家畜采食量与植物补偿生长两方面考虑,在青藏高原高寒草地藏羊单独放牧与牦牛和藏羊1：2混牧的放牧方式较为合理。     

暖季草场不同放牧方式对牦牛藏羊生产力的影响

为探讨中度放牧条件下放牧方式对家畜生产力的影响，开展了牦牛单牧（YG）、藏羊单牧（SG）、牦牛藏羊1∶6混牧（MG1∶6）、牦牛藏羊1∶4混牧（MG1∶4）和牦牛藏羊1∶2混牧（MG1∶2）5个控制性放牧试验，研究了牧草生长季不同生长时期对家畜日增重的影响以及不同放牧方式对牦牛和藏羊暖季增重、牧草营养和家畜采食量的影响。结果表明：1）在牧草返青期和生长期，牦牛和藏羊的日增重显著大于牧草枯黄期（P<0.05）;2）牦牛和藏羊日增重在不同的放牧方式下无显著差异（P>0.05），而牦牛暖季增重在YG下最高，在MG1∶2和MG1∶6相对较高，藏羊暖季增重在MG1∶2中最高，在SG和MG1∶4相对较高；3）不同放牧方式下牧草营养和单位面积家畜采食量无显著差异（P>0.05），单一家畜放牧单位面积增重SG最高，牦牛藏羊两种家畜混合放牧则MG1∶2单位面积增重最高。综上，牧草枯黄期牦牛和藏羊的补饲对于维持其生产性能具有重要的意义，且MG1∶2对于牦牛和藏羊生产是一种较优的组合生产方式。     

冷季补饲精料对放牧牦牛生长性能、养分消化率和血清生化指标的影响

为研究冷季补饲精料对放牧牦牛生长性能、表观消化率和血清生化指标的影响,试验选取健康麦洼牦牛132头,按年龄和体重相近的原则随机分为2组,即对照组和补饲组,每组66头牦牛,补饲组归牧后补饲精料(1 kg/d·头),对照组只放牧。试验期为60 d。结果表明:(1)与对照组相比,补饲组牦牛的总增重和平均日增重显著提高(P 0.05),掉膘降低41.42%,补饲组成年牦牛、犊牦牛的总增重和平均日增重显著高于对照组(P 0.05),成年牦牛掉膘降低55.14%,犊牦牛掉膘降低57.31%;(2)补饲组牦牛粗蛋白质、中性洗涤纤维、酸性洗涤纤维的表观消化率显著高于对照组(P 0.05),分别提高7.56%、9.86%、8.45%,补饲组成年牦牛、犊牦牛酸性洗涤纤维的表观消化率显著高于对照组(P 0.05),犊牦牛提高10.52%,成年牦牛提高10.69%;(3)补饲组与对照组放牧牦牛血清中谷丙转氨酶、谷草转氨酶活性和总蛋白、尿素、葡萄糖、胆固醇、甘油三酯及肌酸激酶含量无显著差异(P 0.05),补饲组成年牦牛血清中总蛋白含量显著高于对照组(P 0.05),提高24.41%。由此可见,冷季补饲精料有助于提高放牧牦牛生长性能和对营养物质的消化率,有利于牦牛冷季保镖,且对犊牦牛的效果优于青年牦牛。     

体外产气法评定天祝几种高山植物的抗营养因子及饲用潜力

比较和分析了6种富含单宁的家畜可饲高山植物粗蛋白、酸性洗涤纤维、粗灰分的含量,并对其酚类物质的含量进行了测定。结合体外产气技术(in vitrogas production method),对各种植物和添加聚乙烯二醇(PEG)的体外产气量和干物质降解率进行测定。结果表明,灌木粗蛋白含量较高,藏沙棘高达14.3%,缩合单宁含量随植物品种不同而变化,藏沙棘、金露梅和珠芽蓼含量分别为42.45,35.24,32.98 g/kg(DM)。添加PEG后,珠芽蓼、藏沙棘、金露梅和鬼箭锦鸡儿的产气量分别增加了36.9%,38.9%,16.4%和8.6%。     

高寒草地主要物种对放牧方式的响应

以环青海湖高寒草地禾本科、莎草科、豆科和杂类草等各功能群的主要物种为研究对象,探讨禁牧和5种放牧方式(牦牛单牧、藏羊单牧、牦牛? 藏羊=1?6混牧、牦牛 ? 藏羊=1?4混牧、牦牛? 藏羊=1?2混牧)下各功能群主要物种频度和个体特征对放牧的响应机制.结果表明:1)在不同的放牧方式下特别是牦牛? 藏羊=1?2混牧条件下,禾本科、豆科和杂类草中适口性好以及生物量大的物种紫花针茅(Stipa purpurea)、洽草(Koeleria macrantha)、早熟禾(Poa annua)频度有所减少,适口性差、植株低矮的物种星毛委陵菜(Potentilla acaulis)频度有所增加,各功能群主要物种的株高均有所降低.2)禾本科、豆科和适口性好的杂类草单株重有所降低,而低矮丛生型的莎草科物种矮生嵩草(Kobresia humilis)和低矮适口性差的根茎型杂类草星毛委陵菜单株重有所增加.3)除禾本科个别物种株高比低于对照,禾本科、莎草科、豆科和杂类草等各功能群主要物种的株高比高于对照.研究表明,青海湖流域高寒草地植物在物种水平对放牧响应明显,而且不同物种之间差异显著(P<0.05),但在功能群水平对放牧响应不显著(P>0.05);相较其他放牧处理,牦牛? 藏羊=1?2混牧处理对高寒草地主要物种的频度和个体特征影响显著.     

牦牛藏羊混合放牧对高寒草地紫花针茅功能性状的影响

植物功能性状是植物响应草地变化的主要指标,对于了解草地发展进程具有重要意义。本试验对牦牛、藏羊混合放牧（不同放牧方式）下对紫花针茅（Stipa purpurea）叶片元素含量（碳含量、氮含量、碳氮比）及种群表型性状指标（植株高度、单株重、叶厚、比叶面积）进行测定,旨在明确放牧方式对紫花针茅的影响。结果显示：不同放牧方式对紫花针茅碳含量、氮含量、碳氮比、叶厚无显著影响,对植株高度、单株重、比叶面积影响显著（P<0.05）,牦牛藏羊1∶4混牧处理下紫花针茅植株高度、单株重、比叶面积受放牧影响最显著（P<0.05）,与禁牧相比,分别降低了39.0%,59.70%,22.8%;相关性分析可知：植株高度、比叶面积、单株重存在极显著正相关关系（P<0.01）;单株重是紫花针茅响应放牧干扰的主要性状指标;综合分析可得牦牛藏羊1∶4混牧处理对紫花针茅功能性状影响最为显著。     

不同放牧方式对高寒草地功能群生态化学计量特征的影响

本研究基于青藏高原东北部高寒草甸化草原设置的控制放牧试验，测定牦牛单牧(YG)、藏羊单牧(SG)、牦牛藏羊1∶6混牧(MG1∶6)、牦牛藏羊1∶4混牧(MG1∶4)、牦牛藏羊1∶2混牧(MG1∶2)和禁牧对照(NG)下禾本科、莎草科、豆科和杂类草的C，N，P含量并计算分析其计量特征。结果表明：各放牧处理增加了禾本科和莎草科的N含量，降低了杂类草的C含量，此外仅YG处理增加了莎草科的P含量；各放牧处理降低了禾本科和莎草科牧草的C∶N，除YG降低了莎草科的C∶P和N∶P以外，其他放牧处理增加了C∶P和N∶P；不同放牧方式下各功能群C∶N，C∶P，N∶P与N，P具有显著的负相关性(P<0.05)。依据中度放牧干扰下植物超补偿性生长的机制和植被生长速率假说，YG促进了莎草科物种的生长，同时也表明N、P在促进植被更新方面起到了重要的作用，是高寒草地植被生长重要的限制性元素。     

杜鹃灌丛草地响应休牧的植被特征变化

初步探讨了不同休牧模式恢复杜鹃灌丛草地的地上生态过程.结果表明,全生长季休牧对灌丛草地灌木片层产生了积极影响,柳、鬼箭锦鸡儿和金露梅等饲用灌木的高度有明显恢复;苔藓和地面枯草存量增加,灌下微生境趋优;灌间草本群落高度、盖度和生物量有不同程度增加;不同休牧模式在生长季各阶段的表现存在差异,8月份草地禾草+莎草与杂类草的产草量之比:全生长季休牧、枯草期轻牧(全年1.67羊单位/hm2)为1.61.全生长季休牧、枯草期重牧(全年3.49羊单位/hm2)为0.73,对照为0.66,全生长季休牧草地的草群得到优化;枯草期高强度放牧也会影响杜鹃灌丛草地的生态恢复.     

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.     

Evaluation of serum concentrations of biomarkers of skeletal metabolism and results of radiography as indicators of severity of osteochondrosis in foals

OBJECTIVE: To determine whether serum concentrations of biomarkers of skeletal metabolism can, in conjunction with radiographic evaluation, indicate severity of osteochondrosis in developing horses. ANIMALS: 43 Dutch Warmblood foals with varying severity of osteochondrosis. PROCEDURE: 24 foals were monitored for 5 months and 19 foals were monitored for 11 months. Monthly radiographs of femoropatellar-femorotibial and tibio-tarsal joints were graded for osteochondral abnormalities. Serial blood samples were assayed for 8 cartilage and bone biomarkers. At the end of the monitoring period, foals were examined for macroscopic osteochondrosis lesions. RESULTS: Temporal relationships were evident between certain serum biomarkers and osteochondrosis severity in foals during their first year. Biomarkers of collagen degradation (collagenase-generated neoepitopes of type-II collagen fragments, type-I and -II collagen fragments [COL2-3/4C(short)], and cross-linked telopeptide fragments of type-I collagen) and bone mineralization (osteocalcin) were positive indicators of osteochondrosis severity at 5 months of age. In foals with lesions at 11 months of age, osteochondrosis severity correlated negatively with COL2-3/4C(short) and osteocalcin and positively with C-propeptide of type-II procollagen (CPII), a collagen synthesis marker. Radiographic grading of osteochondrosis lesions significantly correlated with macroscopic osteochondrosis severity score at both ages and was strongest when combined with osteocalcin at 5 months and CPII at 11 months. CONCLUSIONS AND CLINICAL RELEVANCE: The ability of serum biomarkers to indicate osteochondrosis severity appears to depend on stage of disease and is strengthened with radiography. In older foals with more permanent lesions, osteochondrosis severity is significantly related to biomarker concentrations of decreased bone formation and increased cartilage synthesis.