褪黑激素在毛皮动物生产中的研究应用

褪黑激素(melatonin)是一种吲哚类(indole)激素,由松果腺(pineal gland)分泌。光照是调节松果腺活动的原始因素。光照抑制松果腺活动,黑暗则刺激松果腺产生褪黑激素。随着一昼夜光照和黑暗的交替及一年中长日照和短日照的交替,褪黑激素的分泌呈现明显的周期性变化。动物血液中褪黑激素白天含量低,夜间含量高;长日照期间褪黑激素的分泌少,短日照期间分泌增多。Rollag等(1976)报道了绵羊一昼夜24小时褪黑激素分泌的规律,白天血液中褪黑激素的含量10～     

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     

褪黑激素及其应用

褪黑激素（melatonin,MLT）是由松果腺细胞从血液中摄取色氨酸及其羟化酶逐步合成的一种重要激素。近年来,发现褪黑激素,亦存在于松果腺以外的组织,如视网膜、红细胞以及肠黏膜细胞。     

褪黑激素及其应用

褪黑激素(melatonin,MLT)是由松果腺细胞从血液中摄取色氨酸及其羟化酶逐步合成的一种重要激素.近年来,发现褪黑激素,亦存在于松果腺以外的组织,如视网膜、红细胞以及肠黏膜细胞.     

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。     

褪黑激素在毛皮动物饲养业上的应用现状和前景

褪黑激素简写为MT或MLT , 化学名称为5-甲氧基, N-乙酰色胺, 它由松果腺细胞从血液中摄取色氨酸以及羟化酶而合成的一种重要激素,它不仅存在于松果腺中,而且还存在于松果腺以外的组织,如视网膜、红细胞和肠粘膜细胞.它最早从牛松果腺中分离出的, 因它能使两栖类和鱼类的色素细胞中的色素颗粒凝聚, 从而使皮肤的颜色变浅, 故取名为褪黑激素.现已能人工合成并生产.大量研究资料表明:MT参与了对动物换毛、生殖及其它生物节律和免疫活动的调节, 具有镇静、镇痛的作用, 并展示了在医药、化妆品工业、畜牧业及野生动物养殖业的商业应用前景.     

绵羊母羔血浆中褪黑激素含量与初情期的关系

绵羊松果腺以及它分泌的褪黑激素(Melatonin)与季节发情控制有关。在公羊,松果腺切除或颈前神经节截除可基本上清除光照周期对促性腺激素释放激素、促乳素和睾酮分泌的影响。但母羊,松果体对生殖机能的短期控制似乎不是必需的。最近试验证实:通过口服     

褪黑激素对哺乳动物繁殖生理的作用

对哺乳动物和禽类的早期试验查明,切除松果腺后的反应可以表现为三种:刺激性腺发育、抑制性腺发育或无作用。以不同方法制备的松果腺提取物对动物性腺发育也表现出这三种不同作用。对老鼠松果腺6种吲哚物质的研究结果表明,只有褪黑激素(Melatonin,Mel)、6-羟基Mel和5-甲氧色胺对繁殖系统有作用,其中5-甲氧色胺是通过乙酰化,转变成Mel后起作用的。很多试验表明,虽然其它吲哚物质也有很强的生理作用,但Mel是松果腺中发挥繁殖生理功能的主要吲哚物质。     

褪黑激素及其在畜牧生产中的应用

褪黑激素(Melatonin,MLT),是由松果腺细胞从血液中摄取色氨酸及其羟化酶而合成的一种重要激素,同时也存在于松果腺以外的组织,如视网膜、红细胞和肠粘膜细胞。MLT能使两栖类动物皮肤颜色变浅,对哺乳动物功能起重要调控作用,控制毛皮兽的皮毛生长,在调控鹿茸生长、奶牛产奶量,提高山绵羊产毛(绒)方面均起重要作用。     

埋植褪黑激素诱发水貂冬毛提早生长

用埋植内装褪黑激素(melatonin)的硅橡胶管的方法诱发水貂提早生长冬毛的研究已进行多年。早在1965年,C.C.Rust等人就提出了“激素控制水貂毛皮生长周期”的论文。1969年,Rust和Meyer提出光周期对鼬科动物毛皮生长是受松果腺及其分泌物—褪黑激素调节的。1970年,Adair等还研究了水貂性别之间对褪黑激素反应的差异。1980年J.Rougect     

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.     

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。 …