皂苷调控反刍动物瘤胃发酵和甲烷产量的研究进展

饲料在反刍动物瘤胃内发酵过程中,不仅会造成能量和蛋白质的流失,降低饲料利用率,而且对环境造成污染。皂苷是一类对反刍动物瘤胃发酵有调控作用的植物次级代谢产物。文章综述了皂苷对反刍动物瘤胃发酵及甲烷产量影响的研究进展,并对今后的研究及应用提出了展望。     

植物提取物对反刍动物瘤胃发酵、甲烷产量及生产性能影响的研究进展

植物提取物中含有生物碱、皂苷、单宁和多糖等多种生物活性成分,具有抗菌、促生长、提高免疫力等功能,可以调控反刍动物瘤胃发酵模式,提高氮利用率,降低甲烷排放和提高动物生产性能等,是一种理想的抗生素替代品.文章综述植物提取物对反刍动物瘤胃发酵、甲烷排放、氮利用率和生产性能方面的调控作用,为植物提取物在反刍动物方面的研究和实际...     

植物提取物对瘤胃发酵调控的研究进展

瘤胃微生物虽然可发酵饲料产生挥发性脂肪酸和微生物蛋白为反刍动物供应能量和蛋白质,但是这种发酵过程会造成能量(甲烷排放)和蛋白质(氨氮流失)的损失,从而降低反刍动物的生产性能和污染环境。离子载体抗生素在减少瘤胃能量和蛋白质损失方面效果显著,但是其应用越来越受到限制。因此,寻求抗生素替代物来调控瘤胃发酵成为科学家们研究的热点。近年来,大量研究表明,植物提取物中含有皂苷、挥发精油和单宁等多种生物活性成分,具有抗菌、促生长、提高免疫力和抗氧化等功能,同时具有调控反刍动物瘤胃发酵模式,降低饲料蛋白质损失,减少甲烷排放的功能。文章针对应用于反刍动物饲料的植物提取物的来源、种类、组成特性和应用做了综述,以期为我国植物提取物的产品开发和利用提供参考。     

反刍动物饲料纤维的营养调控作用

提高反刍动物瘤胃的纤维降解率是增加粗饲料利用的有效途径.本文从饲料纤维对反刍动物采食量、咀嚼和反刍,对瘤胃发酵的调控以及对消化、生产性能和健康的影响三个方面综述了饲料纤维的营养调控作用.     

油脂对反刍动物瘤胃发酵、甲烷产量及生产性能影响的研究进展

油脂具有调控反刍动物瘤胃发酵模式、减少甲烷排放和提高动物生产性能等功能,被认为是一种可以替代抗生素药物的天然饲料添加剂。越来越多的研究致力于探讨各种来源的油脂对瘤胃发酵和瘤胃甲烷排放的影响。该文综述了油脂对反刍动物瘤胃发酵、甲烷排放和生产性能的影响,旨在为今后油脂在反刍动物健康养殖应用上提供科学的理论参考依据。     

微量元素在反刍动物生产中的应用

微量元素在反刍动物体内发挥着重要作用,作者阐述了微量元素在反刍动物体内的营养作用,以及其对反刍动物生产性能、繁殖性能和瘤胃微生物的影响。为合理补饲微量元素、调控瘤胃发酵、提高生产性能和繁殖性能提供参考依据。     

体外产气法研究不同钾水平日粮对绵羊瘤胃发酵的影响

<正>近年来通过调控瘤胃发酵来提高反刍动物饲料转化率及生产性能一直是反刍动物营养研究的重点之一。钾对瘤胃微生物的生长以及瘤胃发酵都是必需的,不同钾水平的日粮在很大程度上影响了瘤胃发酵模式及动物的生产性能。20世纪90年代初以来,体外产气法由于能够较好地模拟瘤胃中的发酵历程和     

植物精油对瘤胃发酵的调控作用

瘤胃微生物可降解饲料中营养成分来生成挥发性脂肪酸并合成微生物蛋白来为反刍动物提供能量和蛋白。但瘤胃发酵过程中会有能量损失和蛋白利用效率低下现象发生,进而降低了反刍动物生产性能。植物精油可以与微生物细胞膜作用,可抑制一些革兰阴性菌和阳性菌,进而调控瘤胃微生物发酵作用。论文主要介绍近年来植物精油对瘤胃发酵调控作用研究近况,讨论其作为瘤胃发酵调控剂的可行性。     

日粮中添加活性干酵母对反刍动物的影响

近年来,对反刍动物瘤胃微生物系统的调控已成为研究热点,活性干酵母作为瘤胃发酵的天然调控剂,不仅可改善瘤胃内环境,提高生产性能,而且没有类似抗生素的药物残留问题.     

植物提取物对反刍动物瘤胃发酵和甲烷产量的影响

植物提取物中含有丰富的挥发油、生物碱、萜类、皂苷等化学物质,具有抗菌、促生长、抗氧化和提高免疫力等功能,对反刍动物具有调节发酵模式、提高蛋白利用率、减少甲烷排放等功能,在反刍动物瘤胃调控方面发挥着积极作用。文章针对植物提取物对反刍动物瘤胃发酵和甲烷产量的调控进行了综述。     

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.