有机锌源添加剂的质量与效果评价方法探讨

锌是动物体内必需的微量元素,在体内有300多种酶含有锌或与锌有关,锌还参与DNA、RNA和染色体的结构与功能作用.缺锌会引起机体代谢紊乱,导致蛋白质合成受损,影响动物生长和正常生理功能.不同锌源对锌的吸收利用率和动物使用效果存在较大差异,如无机形式锌易受胃肠环境、日粮组成等很多因素的影响,研究以低剂量的有机锌替代高剂量无机锌对动物生长和生理功能及环境保护有重要的意义.     

甘氨酸锌在动物生产中的应用研究

锌是动物体内的必需微量元素之一,在动物生长发育和健康方面起着关键作用.甘氨酸锌作为有机微量元素具有生物利用率高、减排环保等优势.综述了甘氨酸锌对动物的生长性能、繁殖性能、免疫能力及肠道健康的影响,探讨了动物对甘氨酸锌的需要量,旨在为动物生产中科学利用甘氨酸锌改善动物健康,促进动物生长提供理论依据.     

高锌对断奶仔猪促生长作用的研究

<正>锌是动物体必需的一种微量元素,它做为体内多种酶的辅助因子,参与动物体内的多种生化代谢反应,对动物的生长发育有重要作用。近年来,众多学者发现高锌对断奶仔猪具有减少下痢、提高日增重的作用,并对断奶仔猪日粮中添加高剂量锌的应用效果进行了广泛研究且有了一些新的发现。本文拟就国内外学者对高锌对断奶仔猪的促生长效果以及可能的促生长作用机理做一综述。     

不同锌水平对鹅血液抗氧化酶活性的影响

锌是动物体内200多种酶的组成成分之一,又和300多种酶的活性相关。试验通过调节这些酶的活性来影响动物体内的物质合成与代谢。过去人们对雏鹅日粮中锌添加量的研究主要侧重于对生长性能方面的影响,关于锌水平与鹅抗氧化酶的关系则罕见报道。试验通过测定不同锌浓度对鹅血液中酶的影响,探讨锌影响鹅抗氧化功能的机理,并寻求锌的最适添加量。     

不同水平甘氨酸锌对断奶仔猪生长性能的影响

锌是动物必需的微量元素之一，作为体内200多种酶的必需组分或激活因子，锌广泛参与体内的一系列代谢活动，锌还是许多转录因子的必需组分。动物缺锌会出现生长受阻，厌食，皮肤损坏，骨骼畸形，免疫力及繁殖力下降等症状。仔猪对锌的需求量很高，但饲粮中锌含量较低，且存在许多限制锌吸收的因素，因此仔猪饲粮需额外添加锌。     

酵母锌对断奶仔猪生长性能及抗氧化作用的影响

1973年,世界卫生组织专家委员会确认锌是动物生长所必需的微量元素之一.已证明,锌参与体内120多种酶的生物合成,调节300多种酶促反应,合理的锌水平可以保证动物各组织、器官功能处于最佳的功能状态,促进动物生长,强化防御能力、免疫系统,增强动物对疾病的抵抗能力.目前为止,在畜牧生产中应用的锌有无机锌、有机锌和螯合锌.以酵母形态存在的锌现已用作儿童补锌试剂,为探索其在动物生产中的应用效果,笔者以不同浓度的酵母锌为锌源饲喂断奶仔猪,研究酵母锌与断奶仔猪生长性能及抗氧化作用之间的相互关系,以确定酵母锌在断奶仔猪饲料中合理的添加水平,为酵母锌在饲料生产中的广泛应用提供理论依据.     

甘氨酸锌对断奶仔猪生长性能和免疫器官指数的影响

<正>仔猪早期断奶是养猪生产过程中最重要的环节之一,早期断奶能提高母猪的生产效率,降低养殖成本,但仔猪早期断奶会因多方面的应激因素使生长受阻、腹泻率增加等。锌是动物体内一种重要的微量元素,与体内近300种酶的活性有关,在维持动物健康和正常生理机能等方面具有重要作用。锌作为饲料添加剂被广泛应用于畜牧业生产中,锌添加剂也由最初的无机锌发展到有机锌,其中氨基酸螯合锌已得到广泛应用。研究表明,锌能促进仔猪生长和提高饲料     

不同添加水平甘氨酸锌对断奶仔猪生长性能的影响

锌是动物的必需微量元素之一,通过作为体内200多种酶的必需组分或激活因子而广泛参与体内的一系列代谢活动,而且锌还是许多转录因子的必需组分。动物锌缺乏会出现生长受阻、厌食、皮肤损坏、骨骼畸形、免疫力及繁殖力下降等症状。仔猪对锌的需要量很高,但实用饲粮中锌含量较低,且存在许多限制锌吸收的因素,因此在仔猪饲粮中需要额外添加。     

锌在畜禽生产中的应用现状及对环境污染的研究进展

锌是动物体内必需微量元素之一,广泛参与体内新陈代谢活动,具有重要的生理功能,是迄今为止发现的动物必需微量元素中功能最多的一种。但是,畜禽规模化养殖中为提高畜禽抗病力和生长性能等,饲料中锌添加剂被大量使用,导致排泄物中的锌等重金属含量增加,造成一定的环境污染。本文主要简述了锌在畜禽生产中的应用现状,阐明了锌的危害及钝化措施,以期为养殖中合理使用锌、控制锌污染提供理论参考。     

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     

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.     

Evaluation of serum concentrations of biomarkers of skeletal metabolism and results of radiography as indicators of severity of osteochondrosis in foals

OBJECTIVE: To determine whether serum concentrations of biomarkers of skeletal metabolism can, in conjunction with radiographic evaluation, indicate severity of osteochondrosis in developing horses. ANIMALS: 43 Dutch Warmblood foals with varying severity of osteochondrosis. PROCEDURE: 24 foals were monitored for 5 months and 19 foals were monitored for 11 months. Monthly radiographs of femoropatellar-femorotibial and tibio-tarsal joints were graded for osteochondral abnormalities. Serial blood samples were assayed for 8 cartilage and bone biomarkers. At the end of the monitoring period, foals were examined for macroscopic osteochondrosis lesions. RESULTS: Temporal relationships were evident between certain serum biomarkers and osteochondrosis severity in foals during their first year. Biomarkers of collagen degradation (collagenase-generated neoepitopes of type-II collagen fragments, type-I and -II collagen fragments [COL2-3/4C(short)], and cross-linked telopeptide fragments of type-I collagen) and bone mineralization (osteocalcin) were positive indicators of osteochondrosis severity at 5 months of age. In foals with lesions at 11 months of age, osteochondrosis severity correlated negatively with COL2-3/4C(short) and osteocalcin and positively with C-propeptide of type-II procollagen (CPII), a collagen synthesis marker. Radiographic grading of osteochondrosis lesions significantly correlated with macroscopic osteochondrosis severity score at both ages and was strongest when combined with osteocalcin at 5 months and CPII at 11 months. CONCLUSIONS AND CLINICAL RELEVANCE: The ability of serum biomarkers to indicate osteochondrosis severity appears to depend on stage of disease and is strengthened with radiography. In older foals with more permanent lesions, osteochondrosis severity is significantly related to biomarker concentrations of decreased bone formation and increased cartilage synthesis.