合生素在生长育肥猪生产中的应用效果

抗生素在畜牧业产生了巨大的经济效益。调查表明，抗生素在畜牧业的应用可使猪肉产量提高4％，牛肉产量提高4％。但抗生素的大量使用所伴随的负面效应也日益突出，表现为病原微生物产生耐药性和药物在动物产品中残留，从而对人类的健康产生潜在的危害。饲料中使用抗生素遇到了空前的压力。     

益生菌在饲料添加剂中的应用

随着养殖规模的扩展和养殖理念的更新,抗生素在使用过程中产生的毒副作用越来越引起人们的关注。将益生菌作为饲料添加剂,可以将益生菌的功效和优质饲料的优点结合在一起,成为替代含抗生素饲料的新型饲料,且能起到维持肠道菌群的平衡、提高动物生产水平、减少动物肠道病原微生物和净化环境的作用。虽然目前益生菌饲料添加剂还不能完全替代抗生素类添加剂,但是其应用速度和范围在逐步提高,并将成为养殖业发展的必然方向,前景可期。     

益生菌在猪养殖中的应用

益生菌是一种定殖在动物消化道和生殖系统内,能够对宿主产生有益作用的微生物的总称。益生菌也是替代抗生素的有效制剂之一,被认为是抗生素的"天然"替代品,在猪生产上具有广泛的应用。益生菌适用于猪生产的所有不同生产阶段,它们用于多种目的,例如改善生产性能,减轻疾病,提高畜产品质量以及减少环境污染。为此,本文介绍了益生菌的定义和特征;简述了益生菌在母猪、哺乳仔猪、育肥猪生产中的应用情况;分析了当前益生菌市场的情况和益生菌使用的未来前景。     

微生物饲料添加剂的主要功能及其研究进展

益生菌是当摄入量足够时能对机体产生有益作用的活性微生物.人们常把应用于畜牧业生产上的益生菌称为微生物饲料添加剂.以往研究表明,微生物饲料添加剂具有维护动物肠道健康、缓解不良应激、改善畜舍环境、调节机体脂肪代谢和改善畜产品品质的功能.还有研究者认为,微生物饲料添加剂具有替代抗生素功能的作用.本文旨在就微生物饲料添加剂的主要功能及其研究进展进行综述,为其今后在畜牧业生产上的科学应用及相关研究提供参考.     

动物微生态制剂在养牛业中的应用

众所周知,抗生素在畜牧业上的应用,大大的促进了畜牧业的发展,但随着抗生素的长期应用,其抗药性、药物残留、耐药性等弊端也日益明显.动物微生态制剂也称微生物饲料添加剂,由于其具有无污染无残留,维持动物肠道微生物平衡,提高动物免疫力的特点,近年来在养牛业中被广泛应用.     

饲料中添加抗生素的负面影响及解决措施

抗生素是某些真菌、放线菌、细菌等微生物的代谢产物,由于抗生素饲料添加剂对病原微生物有杀灭作用,节约了大量本来被有害微生物所消耗的营养成分,使动物养分增加,一方面应用抗生素后可延长饲料在动物体内的消化吸收时间,另一方面,可使动物肠壁产生变化,从而有利于营养成分通过肠壁膜增加养分吸收。     

反刍动物饲用抗生素替代物研究进展

抗生素的违规使用威胁着畜牧业的健康发展,寻找可靠的抗生素替代物以减少抗生素的使用已成为当务之急。作者总结了反刍动物饲料中使用的抗生素种类,综述了益生菌、植物提取物、酶制剂、有机酸、抗菌肽、功能性寡糖等主要的反刍动物饲用抗生素替代物的作用机理,重点阐述了反刍动物饲用抗生素替代物对反刍动物瘤胃发酵、微生物区系、免疫机能及生产性能影响的研究进展,并对反刍动物饲用抗生素替代物在实际生产中的应用进行了展望,以期为后续对反刍动物饲用抗生素替代物的研究和应用提供参考。     

乳酸菌在养猪生产中的作用

抗生素作为饲料添加剂在防治动物疾病、提高动物生产性能和增加畜产品数量方面起到了重要的作用,是目前饲料中用量最大,最广泛的添加剂。随着科学技术的发展和人民生活水平的提高,人们发现大量使用和滥用抗生素已经给动物本身、畜产品和环境带来一系列的问题,直接影响着人类的健康。欧盟、美国、日本等国家已经开始限制或禁止在饲料中添加抗生素。微生物饲料添加剂是农业部批准的饲料添加剂,通过改善动物肠道菌群生态平衡从而提高动物健康水平,是有效解决目前疾病泛滥、病菌耐药性强和变异快、动物免疫能力下降的有效手段,是畜牧业可持续发展的动力。在美国食品和药物管理局（FDA）1989年公布的44种微生物饲料添加剂中,其中有28种为乳酸菌,乳酸菌作为益生菌的一种,在养猪生产中具有重要的生物学功能,而且乳酸菌具有无毒副作用、无耐药性、无残留等特点,在养猪生产中逐渐受到重视,应用也越来越广泛。     

动物性食品中抗生素的残留与检测

在畜牧业生产中，为预防和治疗畜禽疾病，促进食用动物的生长和繁殖，提高饲料利用率，经常使用抗生素或在饲料中加入一定量的抗生素作为饲料添加剂。因此，往往在畜禽体内及其产品中残留，并随动物性食品进入人体，对健康产生种种有害影响。抗生素在兽医临床上应用十分广泛，用量越来越大，同添加于饲料内的抗生素一起，造成其在动物性食品中越来越多的残留，势必对人体健康带来不良影响。有些国家动物性食品中抗生素的残留情况相当严重。美国曾有12％肉牛、58％犊牛、23％猪和20％禽肉中检出抗生素。日本有60％牛和92％猪肉中检出抗生素。…     

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.