选择和使用抗生素的误区

几乎所有的人都接触过抗生素,但真正知道怎样使用抗生素的人却为数不多,包括相当一部分基层兽医在内.在使用抗生素的过程中存在不少错误,最大的问题是抗生素的滥用.抗生素的滥用是当前国内畜牧业生产中存在的较为普遍的问题.造成抗生素滥用的主要原因是基层兽医和养猪业者对猪病和抗生素认识理解上的不足,即在抗生素的使用上存在不少误区.其误区主要有以下几方面:     

牛乳中的抗生素及检测

奶牛和人一样都会得病,所以抗生素作为治疗用药被应用于奶牛疾病的医治.抗生素对牛乳的影响甚为重要.治疗奶牛乳房炎时,在饲料中添加青霉素等抗生素.无论是通过口服还是注射进入奶牛体内的抗生素都可以通过奶牛自身的代谢排出体外,牛乳就是牛体抗生素排出体外的一个重要途径.如果牛奶中存在抗生素,则对人体健康有不可忽视的损害.所以在我国乳制品国标中明确规定注射过抗生素的奶牛5d内产的牛乳都不允许出售使用.     

家禽生产中抗生素耐药性的挑战

细菌会对抗生素产生耐药性一直是人类和畜禽健康面临的严重威胁.人们针对抗生素及耐药性之间的关系开展了广泛的研究.然而,通过调整抗生素使用来降低耐药性水平的尝试,其成功具有不确定性.那么抗生素使用是否是唯一(或最显著)影响菌群耐药性持久与否的选择压.任何用作筛选非抗生素耐药性的因素都被称作抗生素耐药性的共选择因素,包括相关抗生素、金属离子和添加的混合物,如消毒剂等.不了解这些共选择因素会导致对耐药性的成因估计不准确,并对降低耐药性的干预措施产生误导.在家禽生产系统中,控制耐药性的主要挑战是我们不了解家禽生产实践中如何筛选抗生素耐受性细菌.控制抗生素耐药性的手段更多依赖于非抗性因素筛选抗性细菌,而不是抗生素的实际用量.     

3种植物多糖与枯草芽孢杆菌协同作用的研究

我国现代畜牧业发展至今,饲料中使用抗生素的品种和添加剂量不断增加,抗生素在养殖生产中的使用问题一直为行业所关注.现阶段整个畜牧业不得不面临的问题是动物肠道及环境中的病源微生物对抗生素耐受能力的增强,导致饲料中抗生素的添加量不断提高.大剂量抗生素的使用,带来的后果是抗生素效率不断降低,并且动物肌肉中的抗生素残留量越来越高,严重危害人类健康.     

如何正确使用抗生素

1正确选择使用抗生素 1.1使用安全性高的动物专用抗生素选择抗生素时应首先根据国家的规定,尽量选用国内外公认的抗生素,慎用人畜共用或与医用同源的抗生素促生长剂.同时应对各种抗生素促生长剂的安全性有所了解,选择安全性高的品种.例如,杆菌肽锌的安全性很高,试验结果表明,其毒性极低,安全可靠.     

添加产淀粉酶大肠杆菌可提高肉鸡性能

抗生素生长促进剂的使用对提高畜禽生产性能和经济效益起了重要的作用.但是,在饲料中添加抗生素生长促进剂可以产生细菌耐药性和药物残留等副作用,危害人类健康.随着人们对抗生素生长促进剂危害的认识日益提高,禁用限用抗生素饲料添加剂的呼声也越来越强烈.不仅许多国家对畜禽产品中的抗生素残留限量提出了极为严格的要求,而且欧盟已经从2006年1月起禁止在饲料中添加所有的抗生素,寻找抗生素生长促进剂的替代品成为一个研究的热点.     

生鲜牛乳中抗生素残留快速检测报告

在奶牛养殖过程中,抗生素经常被用来治疗奶牛各种感染性疾病,有时对乳房炎牛用抗生素直接注射乳房部位进行治疗,而抗生素通过乳牛机体血液残留于牛奶中.一般情况下,用抗生素治疗的奶牛在7 d之内乳中仍残留抗生素,人们饮用含抗生素残留的牛奶及其制品,就相当于低剂量的吸食抗生素,从而破坏人体的正常机能,不利于人体健康.一是使人体产生耐药性,给今后患病使用抗生素治疗带来不良影响;二是抗生素对过敏体质的人会出现过敏反应;三是破坏人体内正常菌群的平衡状态,使菌群失调.     

抗生素与益生素

1 抗生素 抗生素(又名抗菌素)是指细菌、真菌、放线菌等微生物的代谢产物,因对特异性微生物(如细菌、真菌、立克氏体、支原体等)有抑制和杀灭作用,其作用远远超过单纯的抗菌范围,所以称为抗生素.人类在发现抗生素以前,饱受瘟疫的困绕,1928年发现抗生素后,在短短的几十年里,抗生素为人类的健康做出了不可磨灭的贡献.后来,人们还把抗生素用于畜牧业方面,大大的扩展了抗生素的使用范围,促进了畜牧业的发展.     

浅谈兽医临床对抗生素的规范使用

抗生素在兽医临床治疗患病的畜禽中具有重要的地位.本文针对兽医在临床中对畜禽使用抗生素的现状进行分析,并浅谈一些使用抗生素的利弊,并对抗生素的使用原则进行介绍.     

抗生素生长促进剂的历史、作用及发展趋势

抗生素生长促进剂是在食用动物饲养中广泛使用的可以提高动物生产效率的抗生素饲料添加剂.长期以来,抗生素生长促进剂应用于畜牧业生产取得了良好的效果,极大地促进了畜牧业的发展.1996年,全世界抗生素饲料添加剂的用量已经占全部饲料添加剂用量的45.8%,抗生素生产总产量的50%左右用于畜牧业.但是,由于持续低水平饲喂抗生素,抗生素生长促进剂造成的细菌耐药性、畜产品药物残留、过敏中毒反应以及“三致”作用等危害日益明显严重,特别是直接威胁到人类的健康与安全,抗生素生长促进剂的使用越来越受到人们的关注和许多国家的限制.     

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.