褪黑激素在动物生产上的研究进展

褪黑激素是一种在多个物种的多个组织中广泛存在并具有重要生理作用的激素.本文主要对褪黑激素(MLT)的昼夜分泌规律及调控、合成代谢以及目前在动物生产各个方面的研究进展作了概述.     

商品奶中褪黑激素的含量分析

为研究商品奶中褪黑激素的浓度,比较不同品牌、不同品种、不同产地商品奶中褪黑激素浓度的差异,于2015年2月选择北京一中型超市,共采集6个品牌、7个品种,以及3个产地的奶制品,通过放射免疫法检测奶制品中褪黑激素的浓度。结果表明,除无菌砖脱脂鲜牛奶外,同一品种不同品牌,以及同一品牌不同品种商品奶中褪黑激素的浓度无显著差异(P0.05)。品牌1无菌砖脱脂鲜牛奶中褪黑激素浓度显著高于无菌砖纯牛奶、无菌枕纯牛奶、无菌砖鲜牛奶、巴氏奶、儿童奶和酸奶(P0.05),品牌5的无菌砖纯牛奶褪黑激素浓度在3个产地之间无差异(P0.05)。由此可见,北京市售脱脂鲜牛奶中褪黑激素浓度最高,而品牌和产地对其他品种商品奶中的褪黑激素浓度无影响。此外,目前市售牛奶中褪黑激素的浓度基本在15 pg/m L以下,较专门生产的夜间牛奶的褪黑激素浓度低很多,开发高褪黑素夜间奶具有一定的可行性。     

褪黑激素主动免疫对猪生产性能和肉质的影响

通过研究褪黑激素主动免疫对生长猪生产性能和胴体性状的影响,探讨褪黑激素与生长猪养分沉积和肉质的关系。选用20 kg左右健康二元杂交猪10头,按体重相近的原则随机分成2个处理,每个处理5头,分别注射牛血清白蛋白(BSA)和褪黑激素完全抗原,在试验第1天对试验猪进行首次主动免疫,免疫剂量为每只猪18 mg,与福氏完全佐剂充分乳化后,在猪臀部多点肌肉注射。每14 d加强免疫一次,剂量减半,与福氏不完全佐剂乳化后,在猪背部两侧对称多点皮下注射。加强免疫3次。结果表明,褪黑激素主动免疫有提高生长育肥猪生产性能的趋势;提高饲料蛋白质(2.15%)和能量(2.2%)消化率,降低饲料脂肪消化率;褪黑激素主动免疫能显著提高生长育肥猪眼肌面积(36.1%,P<0.05),腹脂比显著增加(P<0.05),但对背膘厚和屠宰率无显著影响(P>0.05);各处理之间肉质指标无显著差异(P>0.05),但褪黑激素主动免疫使滴水损失增加13.13%,大理石纹评分降低11.1%,肌肉丙二醛含量增加10.05%。褪黑激素主动免疫对生长育肥猪生产性能和胴体品质有一定改善作用,但对肉质有一定负面影响。     

褪黑激素促进绒山羊绒毛生长及其作用机制的研究进展

褪黑激素能缩短绒山羊绒毛生长周期,促进绒毛生长,提高绒毛产量。绒山羊绒毛呈现生长、休眠、脱落的周期性变化,与褪黑激素的分泌息息相关。作者综述了褪黑激素的分泌、功能,绒毛的周期性变化,讨论了褪黑激素促进绒毛生长的作用机制,以期为在分子水平阐述褪黑激素对绒毛生长的调控机制提供依据,为将褪黑激素更好地应用于绒毛生产提供参考。     

国产肉粉中褪黑激素的测定

用HPLC法对4个国产肉粉中褪黑激素含量进行了测定,结果表明:用炼油后的油渣制作的肉粉,含有一定量的褪黑激素。该研究结果为国产肉粉在毛皮动物饲料中的合理使用提供参考。     

光照和褪黑激素对獭兔生产性能的影响

<正>研究发现,褪黑激素(MT)对绒山羊的绒毛生长有促进作用。在动物生产中,褪黑激素已经成功用于提高水貂、狐狸和绒山羊等毛皮动物的毛皮产量及其生产性能,关于光照及褪黑激素共同作用对獭兔生产性能的影响研究尚少。试验通过研究不同光照及褪黑激素对獭兔生产性能的影响,旨为褪黑激素在獭兔上的应用提供理论依据及技术支持。     

褪黑激素及其在畜禽生产中的应用

褪黑激素及其在畜禽生产中的应用伍喜林（中国农科院研究生院北京１０００８１）前言近年来，褪黑激素（ｍｅｌａｔｏｎｉｎ）作为动物松果体生物活性最强的物质，其重要性也逐渐得到认识。随着人工合成褪黑激素的成功，它在不久的将来也会广泛用于畜禽生产。对褪黑激素在...     

控制牲畜繁殖期的新方法

由控制哺乳动物生物节律的松果腺所产生的褪黑激素,正被用来控制家畜的繁殖时期。澳大利亚和英国的两个科研小组,已经对绵羊进行了成功的试验,目前正在奶山羊和饲养的红鹿身上作实验。松果腺在控制每天、每季的节律上,起着重要的作用。它在黑暗的夜间分泌出褪黑激素。昼长的季节性变化,即反应在褪黑激素分泌量的变化上。许多种家畜,如     

褪黑激素对动物调控作用的研究进展

褪黑激素主要由脊椎动物的松果腺产生,随后褪黑激素释放到血液中,一般在大脑中保持较高的水平,之后转移到身体的其他器官和组织获得理想的生理反应。一些研究表明褪黑激素及其受体参与调节不同的生理过程。本文综述了褪黑激素对动物的调控作用(抗氧化作用、心血管系统保护作用、调控生殖繁育的作用、免疫系统保护作用、神经系统保护作用),为褪黑激素的研究提供理论基础。     

光照和埋植褪黑激素对非生绒期内蒙古白绒山羊体成分的影响及应用

本文从体成分的角度研究了褪黑激素对内蒙古白绒山羊营养分配的影响,研究结果显示光照时间和埋植褪黑激素显著影响绒山羊的有关激素水平,进而影响体成分组成。随着光照时间的缩短,绒山羊的体脂肪含量增加,体蛋白含量减少;光照相同条件下,埋植褪黑激素组的体脂肪含量高于不埋植组,体蛋白含量低于不埋植组,短光照和埋植褪黑激素之间有显著(P<0.01)的互作效应。证明了光照和褪黑激素在动物营养分配中的作用,为褪黑激素在生产实践中的合理应用提供理论依据。     

Muscle relaxants in canine anaesthesia 1: History and the drugs

The history of the introduction of muscle relaxants into medical and veterinary anaesthesia is discussed. It is interesting to note that the compounds were used in animals for therapeutic purposes some 100 years before their introduction into human anaesthetic practice. The concept of the triad approach to anaesthesia by separate consideration of the three components of narcosis, reflex depression and muscle relaxation is considered. The properties of the depolarising and non-depolarising muscle relaxant drugs are described. The only depolarising relaxant which is in common use is suxamethonium which produces an initial depolarisation of the muscle end-plate which is accompanied by fasciculation of muscle and is non-reversible. There are a number of non-depolarising or competitive muscle relaxants which are available for use in the dog. They are reversible by anticholinesterase drugs and are potentiated by volatile anaesthetic agents. The properties of the more recently introduced compounds atracurium besylate and vecuronium bromide are considered in the light of their differences when compared with the older compounds.     

牛瑟氏泰勒虫病致病机理的研究进展

牛瑟氏泰勒虫病是由蜱传染的一种血液原虫病。近年来,随着养牛业的发展,牛瑟氏泰勒虫病的发生呈上升趋势,尤其是引进牛和改良牛的发病率和致死率均较高,给养牛业带来了巨大的经济损失。本文对近年来牛瑟氏泰勒虫病的病原体、流行病学、病理学和致病作用等与此病的致病机理相关的方面的研究进展作一总结,以便广大兽医工作者对此病有更加深入的认识。     

Relationship between ultrastructure and specific functions of macrophages

The main function of the macrophages, which is to ingest and degrade any foreign molecules or particles penetrating the organism, appears in the development of the different structures implicated in endocytic activity. The macrophage's high endocytic property first appears in its irregular shape and the large number of extensions of the cell membrane, allowing the rapid capture of extra-cellular material. Adhesion between macrophage cell surface and molecules or particles is greatly enhanced by the presence of varied kinds of receptors: lectin-like receptors which bind specific sugars or highly specific receptors such as Fc and C3b receptors, which increase phagocytosis of opsonized microbes. The microbicidal properties reside in part in the production of superoxide anions which result from the activity of a NAD(P)H oxidase. This enzyme is located in the plasma membrane. Its activity could be demonstrated with a cytochemical method, on the cell surface and along the phagosome membrane. It is, however, very weak in resident macrophages and increases after stimulation or activation. The second kind of bactericidal property corresponds to cationic proteins located in lysosomes. After fusion between lysosomes and phagosomes, they contribute to microbe killing by permeabilizing microbe envelopes. Lysosomes, which contain diverse acid hydrolases and are responsible for the degradation of ingested material, play a crucial role in macrophage endocytic activity. Their number increases in parallel with endocytic activity during macrophage differentiation and is particularly high after ingestion of degradable material. Contrary to polymorphonuclear leukocytes, macrophage is very poor in granules containing peroxidase. The latter, which are rather abundant in monocytes, disappear during macrophage maturation. They do not seem thus to be implicated in macrophage microbicidal activity. Endocytosis is accompanied by rapid and intense exchanges between the different membrane compartments of the cell (plasma membrane, pinosomes or phagosomes, endosomes, lysosomes, Golgi apparatus, etc.). These exchanges seem to occur by transitory fusions between vesicles coming from different compartments, rapidly followed by their recycling to their original compartment. This system of membrane shuttle has been clearly observed after formation of phagosomes or pinosomes in which the internalized plasma membrane is recycled back to the cell surface within a few minutes after their formation. This membrane traffic is especially intense in macrophages, the endocytic activity of which is very high, but it also exists in all cell types.(ABSTRACT TRUNCATED AT 400 WORDS)     

Characterization of TLR4 signaling in water buffalo (<Emphasis Type="Italic">Bubalus bubalis</Emphasis>)

Lipopolysaccharide (LPS) treatment of Peripheral Blood Mononuclear Cells (PBMC) isolated from the water buffalo resulted in the activation of TLR signaling intermediates as supported by the western blot of pERK. Activation of ERK resulted in phosphorylation of IκB-α which lead to its degradation which in turn followed by nuclear translocation of NF-κB, which is also supported by the western blot analysis. The nuclear translocation of NF-κB culminated in the induction of mRNA expression of TNF-α. Thus this study demonstrates the TLR signaling in PBMCs of water buffalo which is as similar to that reported earlier in mice and human beings.     

Value of so called cholestasis markers in the dog: an experimental study

In experimental bile obstruction in dogs, the most sensitive change in blood plasma composition is the increase in alkaline phosphatase activity which occurs after eight hours. Maximum alkaline phosphatase activities (approximately 100 times normal values) occur between the fifth and the 14th day. The increase in activity is accompanied by smaller increases in gamma-glutamyl transferase activity, and total bilirubin concentration also increases to a smaller extent and less regularly. Cholestasis also induces an intense cytolysis which is demonstrated mainly by increases in glutamate dehydrogenase and alanine amino transferase activities which are more intense and lasting than those induced by 0.5 ml/kg carbon tetrachloride.     

热应激诱导的氧化应激对动物肠道组织的损伤

热应激是一种常见的非特异性应激,给畜牧业带来较大的损失。肠道组织在热应激作用下易发生缺血缺氧,肠道细胞产生氧化应激,造成细胞凋亡,引起肠道组织损伤。而肠道作为动物机体吸收营养、屏障病原体最为重要的器官,当其受到损伤时将直接影响到动物机体的生长发育及健康状况。本文从热应激诱导肠道细胞产生氧化应激,氧化应激对肠道的损伤,以及热应激诱导细胞凋亡途径等方面,结合国内外近年来研究进展作一综述。     

西式香肠的研制

西式香肠是主要的肉制品之一,深受人们喜爱。本文进行西式香肠的加工试验,试制了色泽,气味,口感,组织状态等俱佳的产品。     

种猪场伪狂犬病的净化策略

猪伪狂犬病是由伪狂犬病毒引起的一种以母猪繁殖障碍和仔猪高死亡率为主要特征的急性、热性高度接触性传染病。2011年以来猪伪狂犬病毒变异株导致了免疫猪群暴发该病,对养猪业造成较大的经济损失。因此,种猪场应抓住严防非洲猪瘟的有利契机,同时做好猪伪狂犬病的净化非常重要。文章简要综述了国内外常用的净化方案、净化措施,为养猪场实施净化提供参考。     

从空间和隐喻认知角度看介词的多义

空间概念是人类认识过程最早形成的概念之一，认知的发展和深化是空间概念向新的领域扩展。隐喻在这一发展过程中起着重要的作用，隐喻的本质就是用其它的措辞、事物、概念来理解和体验另一种事物和概念。这样的概念隐喻导致了语言隐喻。语言表达实际上都经历了一个先出现概念隐喻化，然后在表达形式上通过语言隐喻而扩展词义的过程。本文拟从空间认知和隐喻认知角度分析一些介词由空间意义扩展致其它意义的过程，从而说明一词多义的理据性和系统性，旨在对英语的教学和学习有所启发。