营养素对水生动物瘦素基因表达的影响、瘦素的作用及其机理

瘦素(leptin)是一种蛋白质激素。鱼类瘦素主要由肝合成和分泌,参与调节摄食、代谢、生长、免疫、繁殖、神经及造血细胞发育等。本文综述了瘦素的功能及作用机理、营养素对水生动物瘦素基因表达的影响,旨在进一步理解和深入探讨水生动物瘦素的作用及机理、营养素对水生动物瘦素基因表达的影响及其机制,这对理解摄食、能量代谢调控的机制具有科学理论意义;能为有计划、有目的、有效地控制水生动物体重、脂类沉积和能量代谢,根据需要生产理想、优质和健康的水产品提供基础依据,同时为调控人类肥胖、维护健康、提高生产力等提供参考。     

牛磺酸对水生动物主要营养代谢 和基因表达的影响及机理

研究发现牛磺酸越来越多的功能,在鱼类营养、代谢、免疫调节、诱食、生长发育、繁殖、渗透压调节、细胞膜保护和抗缺氧等方面都发挥重要的作用。文章主要综述牛磺酸对水生动物主要营养素——蛋白质、脂肪、糖类代谢和基因表达的影响及其机理。旨在深入理解、研究、掌握牛磺酸影响水生动物主要营养代谢和基因表达的规律和机理,以便更好地应用牛磺酸调控和促进水生动物生长发育,提高生产效率。     

瘦素与哺乳动物繁殖活动关系的研究进展

近二十年来的研究发现,瘦素除了参与哺乳动物摄食及能量代谢平衡过程的调节外,还作为一种代谢信号,通过作用于下丘脑—垂体—性腺轴、胎盘和子宫等来调控哺乳动物的繁殖过程。瘦素基因不仅是研究家畜生长发育、肉质等性状的重要候选基因,而且由于瘦素在调控哺乳动物胚胎附植过程中扮演的重要角色,它也是研究家畜多胎性状的重要候选基因之一。研究瘦素及其受体基因的功能及作用机制具有重要的科学意义和潜在的应用价值。文章主要就瘦素对哺乳动物初情期的启动、生殖器官及性腺的发育、生殖激素的分泌、胚胎附植等繁殖活动的调控,以及性别与年龄、妊娠与哺乳、繁殖节律等对瘦素分泌的影响等方面进行综述。     

高度不饱和脂肪酸对水生动物代谢的影响及其机理

高度不饱和脂肪酸(HUFAs)是机体必需的脂肪酸(EFAs),功能多而重要。然而,在现实研究中,从脂肪或脂肪酸的角度研究其对机体影响的多,专题研究HUFAs的少,以致对HUFAs的影响及其机理的研究不够全面。本文概述HUFAs对水生动物代谢的影响及机理,重点综述HUFAs对脂肪酸代谢、蛋白质代谢、糖(能量)代谢、核酸代谢的影响及其机理,以便进一步深入研究、掌握HUFAs影响水生动物代谢的规律和调控机制,有效地应用HUFAs调控水生动物代谢,改善水生动物的生长发育,促进其健康养殖,提高生产效率,增加社会效益和经济效益。     

营养素对水生动物生长发育相关基因表达的影响及机理研究

营养素是人和动物包括鱼类进行新陈代谢的基础,对机体影响很大。文章综述了营养素对水生动物生长发育相关基因表达影响和机理研究的进展,旨在对其进行深入研究,以便更有效地利用营养素调控水生动物,提高它们的代谢、生长发育和生产性能,促进养殖渔业的健康生态发展,提高经济效益和社会效益。     

瘦素（leptin）与雌性哺乳动物的繁殖活动关系的研究进展

随着对瘦素研究的不断深入,发现其不仅参与食物摄入和能量平衡,而且对雌性哺乳动物的繁殖活动也发挥着重要的调节作用。本文主要就瘦素对母畜初情期的启动、发情、早期胚胎发育、受精卵的着床、妊娠的维持、胎儿的生长发育、乳腺发育和乳汁分泌等繁殖活动的影响进行综述。     

代谢信号对能量影响猪卵泡发育的作用

动物体内的许多激素和因子通过内分泌活动把能量摄入和繁殖系统联系起来。卵巢上卵泡的发育是雌性动物繁殖系统中的重要因素,是繁殖性能的基础。猪的生产是人们生活中主要的肉类来源之一,能量对猪卵泡发育的影响日益受到关注。日粮能量水平的变化会影响到体内循环与营养代谢相关的激素和因子,而这些激素和因子的变化可能会作为代谢信号对卵泡的发育产生影响。这些代谢信号包括胰岛素、瘦素和胰岛素样生长因子-Ⅰ等。研究表明,代谢信号对下丘脑、垂体和卵巢均有影响。在胰岛素、瘦素和胰岛素样生长因子-Ⅰ等代谢信号的介导下,日粮能量营养因素通过改变下丘脑-垂体-卵巢轴的活性,对雌性动物的卵泡发育产生影响。     

菲对水生动物繁育和生长的影响及机理

菲(Phe)是一种典型的多环芳烃类(PAHs)化合物,能致毒、致畸和致癌等,极易在水环境中累积,并可通过食物链传递,难以代谢降解,是全球普遍存在的持久性有机污染物,严重威胁人类和水生动物健康。本文主要综述菲对水生动物繁殖、发育和生长的影响及机理,旨在更深入研究之,有效地控制和防治菲对水生动物的危害,为保护水生生物和生态环境提供参考。     

壳聚糖在水产养殖中的研究进展

壳聚糖具有广谱抗菌性,对革兰氏阴性菌和革兰氏阳性菌都具有抑制和杀灭作用,并且可以通过提高水生动物先天性免疫和获得性免疫的方式提高水生动物免疫力,进而提高其疾病抵抗能力。同时壳聚糖能提高肠道消化酶活性、促进肠道有益菌繁殖、抑制有害菌繁殖,可通过这种方式促进水生动物生长,降低饵料系数。     

家禽维生素营养及其添加量变化规律

维生素是家禽维持正常生长发育、繁殖所需的微量营养成分,其主要作为营养代谢中的辅酶调节机体新陈代谢和能量转变。饲料中添加维生素可有效调节营养物质的消化、吸收和代谢,增强家禽抗应激能力,激发和强化机体免疫机能,改善产品品质,提高家禽的繁殖性能、生产性能及养殖业经济效益。     

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。     

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。     

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。     

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。 …     

鸡败血支原体垂直传播模式及其阻断方法

以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。     

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.