日粮锌硒水平对肉鸡盲肠扁桃体结构的影响

锌和硒作为动物体的必需微量元素，是免疫器官生长发育和免疫应答所必需的营养因子，对体液免疫和细胞免疫都有促进作用。所以，畜牧生产实践中，常在动物日粮中添加锌和硒微量元素，以促进动物正常的生长发育和免疫功能。但是，当锌和硒缺乏或过高时，也可导致动物胸腺、脾脏、腔上囊等免疫器官生长发育不良，     

微量元素锌在养殖生产中的应用

锌是动物体所必需的微量元素之一.在必需微量元素中,锌的功能最多,作用最广.它是多种酶和胰岛素的组成部分,不仅参与和影响体内的蛋白质、碳水化合物、脂类和维生素的代谢过程,而且与胰岛素、促肾上腺素等激素的分泌活动有关.动物如果缺锌,会引起机体代谢功能紊乱、平衡失调等现象,影响动物正常的生长发育,严重时会出现各种临床症状,甚至发病死亡.     

微量元素锌与动物生殖

锌是动物体必需的微量营养元素,有着重要的生物学功能,近年来,随着对锌研究的深入,越来越多的人们认识到锌与动物繁殖机能的关系密切,锌缺乏可直接影响着动物的繁殖机能。 一、锌对生殖的作用 锌在动物体内广泛分布,主要集中于睾丸、附睾和前列腺等器官中,其中精液内含     

动物缺锌的研究进展

锌是动物体所必需的微量元素之一。在必需微量元素中,锌的功能最多,作用最广。它是多种酶和胰岛素的组成部分,不仅参与和影响体内的蛋白质、碳水化合物、脂类和维生素的代谢过程,而且与胰岛素、促肾上腺素等激素的分泌活动有关。它具有促进味蕾细胞迅速再生,调节食欲,抑制肠道有害菌,提高消化系统分泌机能及许多酶活性等作用,从而维持动物健康和促进生长发育。     

禽类缺锌症的研究进展

１概述锌是动物营养必需的微量元素，对动物的生长发育、免疫功能等方面有着重要的影响。缺锌动物生长发育受阻，表现出各种临床症状，甚至发病死亡。禽类缺锌症的研究始于５０年代后期，O’Dell和Savage于１９５７年首次证明锌是家禽日粮中必需的微量元素，随后国内外学者的大量研究显示饲喂低锌日粮能诱发禽类缺锌症。本文对禽类缺锌症的发病机制、发生原因、临床症状、病理变化及防治等方面作一综述。２锌的生理学功能及缺锌症的发病机制许多学者探讨了缺锌症的发病机制，目前认为机体锌缺乏会影响锌酶、内分泌和免疫系统功能的正常维…     

锌是动物营养所必需的微量元素

50多年前 Todd 发现锌为大鼠和小鼠膳食所必需,此后一些学者发现饲养场动物中有锌缺乏病,并广泛开展了实验动物模型研究,从而确认锌对于动物的生长和发育是一种极其重要的微量元素。新近研究表明,心脏病、肝脾肿大、性腺功能减退和癌症等都与锌在动物体内的含量有关。本文仅就锌     

动物缺锌的临床症状及防治措施

锌是动物体所必需的微量元素之一。在必需微量元素中,锌的功能最多,作用最广。它是多种酶和胰岛素的组成部分,不仅参与和影响体内的蛋白质、碳水化合物、脂类和维生素的代谢过程,而且与胰岛素、促肾上腺素等激素的分泌活动有关。它具有促进味蕾细胞迅速再生,调节食欲,抑制肠道有害菌,提高消化系统分泌机能及许多酶活性等作用,从而维持动物健康和促进生长发育。动物如果缺锌,会引起机体代谢功能紊乱、平衡失调等现象,影响正常的生长发育,严重时会出现各种临床症状,甚至发病死亡。许多学者相继研究发现猪、鸡、牛、羊、狗、火鸡、鹌鹑等动物的…     

离子选择性电极法对饲料中氟含量的测定

氟在自然界中分布十分广泛,是地球上广泛存在的机体生命活动所必需的微量元素之一[1],与动物体的健康有一定的关系,如对动物的生长发育、生殖能力、神经系统、骨骼代谢及免疫系统均有影     

微量元素锌在养殖生产中的应用

锌是动物体所必需的微量元素之一。在必需微量元素中,锌的功能最多,作用最广。它是多种酶和胰岛素的组成部分,不仅参与和影响体内的蛋白质、碳水化合物、脂类和维生素的代谢过程,而且与胰岛素、促肾上腺素等激素的分泌活动有关。动物如果缺锌,会引起机体代谢功能紊乱、平衡失调     

锌对种公牛繁殖性能的影响

锌是种公牛营养中一种重要的必需微量元素。早在1921年人们就发现锌与雄性动物的生殖机能有关。近年来的研究证实,饲料中锌不足会导致公畜的睾丸生长发育停止,生精上皮萎缩,垂体促性腺激素和性激素的释放减少,第二性征表现不足或不表现,性欲降低。严重锌缺乏还会导致精子发生完全停止。本文拟就锌与种公牛繁殖性能的关系作一综述。     

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。     

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。     

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.