反刍动物饲料组合效应在养分吸收和能量利用上的研究进展

饲料间组合效应是指来自不同饲料来源的营养物质、非营养物质及抗营养物质间互作的整体效应。反刍动物饲料间的组合效应表现得更为突出和普遍。组合效应可能发生在消化和组织代谢2个层面上,但是由于组合效应的复杂性,目前的研究尚未形成系统的理论。本文综述了反刍动物饲料间组合效应的概念、发生,重点分析了组合效应发生时组织代谢层次上可吸收养分平衡性和能量利用的变化。     

反刍动物木本饲料的组合效应

本文综述了反刍动物木本饲料的组合效应,并对该类饲料(多含次生代谢物)的组合效应进行了分类,指出了其与常规饲料组合效应的异同及今后值得重点研究的几个问题。同时还就此类饲料组合效应的研究方法进行了比较,指出应在体外产气技术的基础上结合动物饲养试验来进行木本饲料的组合效应及其营养代谢机理的研究。     

反刍动物饲料组合效应的衡量指标及评估方法综述

反刍动物饲料间的组合效应的衡量指标一般包括:采食量,消化率和生长性能.研究组合效应尚无统一的标准方法,归纳现有的方法,主要可以分为动物试验、体内消化代谢试验和体外试验.三种组合效应的研究方法各有优缺点,我们可以根据试验目的和试验条件来选择合适的方法.本文分别从饲料间的组合效应、衡量指标及其研究方法等方面进行了综述,以供...     

反刍动物日粮组合效应的研究进展

从传统饲养体系的局限性到组合效应的概念、衡量指标类型、试验研究、发生机制、等方面综述了反刍动物日粮组合效应的研究方法与应用.     

奶牛常用3种粗饲料间组合效应的研究

通过短期人工瘤胃技术研究了奶牛常用3种粗饲料混合料的组合效应,旨在提高粗饲料的营养价值。将苜蓿干草、青贮玉米秸和羊草基于干物质分别按100:0、80:20、60:40、40:60、20:80和0:100比例两两组合,根据发酵结束后的产气量(GP)、微生物蛋白产量(MCP)和代谢能(ME)分别计算单项组合效应指数和多项组合效应指数(MFAEI),结果表明:用单项组合效应指数评价组合效应的结果不完全一致,采用MFAEI进行综合评价时,青贮玉米秸-苜蓿配合比例为60:40时产生最大正组合效应,MFAEI为0.12;青贮玉米秸-羊草配合比例为40:60时产生最大正组合效应,MFAEI为0.83;苜蓿-羊草配合比例为80:20时产生最大正组合效应,MFAEI为0.09。     

体外产气法评定不同来源中性洗涤纤维与粗蛋自质间组合效应

利用体外产气法研究了羊草中性洗涤纤维(NDF)、苜蓿NDF和玉米青贮NDF与豆粕组合体外发酵特性及组合效应.结果表明:体外评价时,所有的组合均发生正的组合效应.羊草NDF与豆粕组合时,当NDF/CP为3.4出现显著正组合效应.在NDF/CP为2.6时有最大正效应值发生;苜蓿NDF与豆粕组合时.当NDF/CP为3.0出现显著的正组合效应,最大正效应值发生在NDF/CP为2.6;青贮NDF与豆粕组合时,当NDF/CP为3.8时出现显著的正组合效应,最大正效应发生在NDF/CP为1.8.随着蛋白质比例的提高,正效应也提高,在一定的NDF/CP值(2.6)时达到最大值,随着蛋白质比例的再次提高,正效应又有下降.     

花生蔓与4种粗饲料间组合效应的研究

为了探讨花生蔓与其他粗饲料间的组合效应,本研究将花生蔓分别与羊草、青贮玉米秸、全株玉米青贮和干玉米秸以0∶100、20∶80、40∶60、60∶40、80∶20、100∶0比例进行组合,每个组合3个重复,利用体外瘤胃发酵技术,分析产气量、产气参数、产气量组合效应、微生物蛋白质产量、微生物蛋白质组合效应和综合组合效应.结果表明:1)在产气特性方面,各组合在产气参数上差异显著(P＜0.05),花生蔓产气速率显著高于其他4种粗饲料,潜在产气量全株玉米青贮最高,青贮玉米秸次之.2)在产气量组合效应方面,12、24、48h花生蔓与青贮玉米秸、干玉米秸及羊草组合,均是当花生蔓占20％时,产生最大正组合效应(P＜0.01)；当花生蔓占40％时,与全株玉米青贮组合产生最大正组合效应(P＜0.01)；当花生蔓占80％时,各组合均产生最大负组合效应(P＜0.01或P＜0.05).3)在48h微生物蛋白质组合效应方面,除花生蔓与羊草组合中花生蔓占20％和40％时产生正组合效应外(P＜0.01),其余均为负组合效应(P＜0.01),其中花生蔓占80％时各组合均产生最大的负组合效应(P＜0.01).4)在48h综合组合效应方面,当花生蔓占20％时,花生蔓与青贮玉米秸、干玉米秸和羊草均产生最大正组合效应；当花生蔓占40％时,花生蔓与全株玉米青贮组合产生最大正组合效应；当花生蔓占80％时,4个组合均产生最大负组合效应.综上所述,在本试验条件下,花生蔓与青贮玉米秸、干玉米秸和羊草均以20:80组合效果最好,花生蔓与全株玉米青贮40:60组合效果最好.     

反刍动物含次生代谢物饲料的组合效应

文章综述了反刍动物含次生代谢物饲料的组合效应,并对该类饲料的组合效应进行了分类,指出了其与常规饲料组合效应的异同及今后值得重点思考的几个问题。同时还就此类饲料组合效应的研究方法进行了比较,指出应在体外产气技术的基础上结合动物饲养试验来进行含次生代谢物饲料的组合效应及其营养代谢机理。     

反刍动物饲草组合效应的研究

利用体外法,通过产气量、干物质(DM)和中性洗涤纤维(NDF)降解率3个指标,对苜蓿、柠条和玉米秸秆的营养价值及组合效应进行研究。结果表明,(1)玉米秸秆与苜蓿产气量、DM动态降解率、NDF动态降解率的组合效应,分别为75∶25、55∶45、75∶25的正组合效应最高,(2)柠条与苜蓿产气量、DM动态降解率、NDF动态降解率的组合效应,分别为75∶25、75∶25、75∶25正组合效应最高。     

五种饲草间组合效应的综合评定研究

采用体外法,测定五种饲草不同组合的pH值、24h累积产气量、微生物蛋白产生量、氨态氮、总挥发性脂肪酸、有机物质降解率,应用组合效应综合指数原理对五种饲草组合效应进行研究。结果表明:豆科饲草与禾本科饲草之间的组合存在着明显的正组合效应;筛选出3个最优组合:组合1,苜蓿/沙打旺/黑麦草(40/40/20);组合3,苜蓿/沙打旺/狼尾草(40/40/20);组合6,苜蓿/黑麦草(60/40)。     

Problems and possibilities into the next decade involving beef cattle breeding research in the southern region: experiment station herds.

Opinions on expected support of animal breeding and genetics research into the next decade were requested from heads of Departments of Animal Science and directors of agricultural experiment stations in the Southern Region and from directors of agricultural experiment stations outside the Southern Region. A majority of administrators in all three groups expect a reduction in assignment of state appropriated funds for beef cattle breeding research compared with total support available. Cattle numbers and land areas assigned to breeding and genetics research may be more limited in the future. Directors of agricultural experiment stations expect animal breeding scientists to work more closely with scientists in biotechnology and to become more involved in multidisciplinary research to reduce the costs associated with maintaining large herds of cattle. Departments of Animal Science do not expect to reduce significantly the number of animal breeding positions, but they may reassign some that come open to balance departmental opportunities. Animal breeding scientists will be needed to educate graduate students, teach classes, and handle research responsibilities as in the past.     

一氧化氮对下丘脑-垂体-卵巢轴的生理调控

一氧化氮(NO)是一种重要的多功能因子,能够介导许多生理功能,其中包括不同的生殖过程,如调节卵泡的发育、排卵、卵母细胞减数分裂的成熟等。虽然近年来科学家对NO在卵巢生理功能方面的影响有了初步的认识,但是NO作用的准确机理尚需深入探讨。今后的研究目标是要证实卵巢机能不良是否与NO合成相关,以及是否能通过NO治疗克服这些缺陷。文章着重介绍了NO对下丘脑垂体水平的影响,以及对卵巢生理功能(类固醇激素合成,卵泡生长,排卵,黄体的功能和衰退等)调控的研究进展。     

植物多糖的提取工艺和方法

早在20世纪40年代,科学家们就开始了对多糖的研究。多糖由于其具有的免疫促进作用,以及抗衰老、抗肿瘤、抗辐射等作用,受关注程度日渐增加。本文将多糖的提取工艺和方法进行了简要的归纳,并对其优劣进行了分析,希望为该领域的科研工作者提供参考。     

Contributions of Citizen Scientists and Habitat Volunteers to Monarch Butterfly Conservation

Volunteers can contribute to wildlife conservation by protecting and restoring habitat, or by collecting citizen science data. Much remains unknown about how citizen scientists contribute to conservation beyond data collection, or the extent that volunteering with citizen science or habitat conservation is associated with increased participation in other forms of conservation. We surveyed citizen science and habitat volunteers from monarch butterfly (Danaus plexippus) programs. Both types of volunteers conducted conservation outreach and created and managed monarch habitat. Habitat volunteers were more likely to create new habitat for monarchs in urban or suburban areas, whereas citizen scientists were more likely to maintain existing habitat in rural areas. Most volunteers increased their participation in conservation after joining a formal monarch project. Our results provide information about the capacity for habitat volunteers to engage in conservation, as well as evidence of an unexplored benefit of citizen science, the creation and protection of habitat.     

流感病毒检测方法研究进展

近些年,流感在全球范围的频繁暴发,使科研工作者关注的焦点转移到对流感病毒进行方便、快速、准确的鉴定上.论文介绍了国内外流感病毒的检测方法,重点介绍了免疫学检测方法,尤其是酶联免疫法和胶体金免疫标记法.通过对各方法优缺点的比较,提出了免疫学检测方法在方便、快速检测流感病毒方法中的特有优势,尤其是胶体金免疫标记法和酶联免疫...     

Influence of stress and nutrition on cattle immunity.

Today, the scientific community readily embraces the fact that stress and nutrition impact every physiologic process in the body. At last, the specific mechanisms by which stress and nutrition affect the immune function are being elucidated. The debate among animal scientists concerning the definition and quantification of stress as it relates to animal productivity and well-being is ongoing. However, an increased appreciation and understanding of the effects of stress on livestock production has emerged throughout the scientific community and with livestock producers. The intent of this article is to provide an overview of the general concepts of stress and immunology, and to review the effects of stress and nutrition on the immune system of cattle.     

Critical perspectives in animal agriculture: a response

People who work in the animal industries are faced with questions and criticisms about a variety of contentious issues, including animal management practices, ethics, diversity in animal agriculture, and animal welfare. Formulating responses to these questions requires a critical evaluation of our own work and open discussion of these controversial issues. Effective debate on these issues can be accomplished only with input from philosophers and social scientists skilled in such discussions, in addition to animal scientists. Therefore, animal scientists must engage in discussions of controversial issues among themselves and with entities outside agriculture. Furthermore, we must accept responsibility for the application of research results and any potential negative consequences. Because society is increasingly concerned with issues of animal welfare and the effects of new technologies, we should increase communications and transparency with the public. Increased diversity of race and gender will increase the ability of animal agriculture to connect with our stakeholders and to communicate the relevance of our work to society. Animal scientists need a professional ethic that espouses a higher level of understanding and commitment to philosophical discussions of contentious issues.     

土壤联合固氮菌的研究进展

面临人类社会普遍出现的粮食、人口、环境、能源、资源等问题的困扰,从可持续发展的角度出发,生物固氮逐渐引起了各国科学家的重视,测试技术的进步及细胞工程与基因工程等技术的出现使生物固氮的研究日趋深入。通过阐述生物固氮中细胞联合固氮的研究现状及其方法与手段,为与之相关的研究者提供了参考。     

鹿茸活性成分及其药理功能的研究进展

鹿茸是我国传统的名贵中药,它的化学成分和药理功能比较复杂。近年来,许多科学家对鹿茸的药理作用进行了深入研究,包括免疫增强、神经保护、生殖促进、抗骨质疏松、抗衰老、抗肝纤维化和抗关节炎等方面的药理作用。文章对鹿茸的活性成分及其药理作用的研究进展作一综述,旨在为进一步开发、利用鹿茸提供相应的理论依据。     

中俄兴凯湖湿地水鸟迁徙调查

兴凯湖是亚太地区水乌重要迁飞区和栖息繁殖地。中俄兴凯湖国际自然保护区2005年共同开展的候乌迁徙调查数据，在春秋两季对兴凯湖迂徙水乌进行了调查，共统计到水乌79种80余万只，主要为雁鸭类，占总数量的96％以上。本文还对兴凯湖水域候乌迂徙的特点及影响鸟类迂徙的因素进行了分析，提出了兴凯湖湿地中俄联合保护鸟类资源的建议。