猪尿液中抗菌药物快速筛选拭子法的建立

为防止抗菌药物在动物性食品中的残留,以枯草芽孢杆菌为受试菌,建立一种检测活体动物尿液中抗菌药物残留的快速筛选拭子法,进行宰前活体检疫.添加试验测定猪尿液中5类抗菌药物最低检测限分别为:β-内酰胺类青霉素和氨苄青霉素均为0.05mg/L;氨基糖苷类庆大霉素0.05mg/L、新霉素0.4mg/L;四环素类金霉素0.1mg/L;大环内酯类红霉素0.05mg/L和氟喹诺酮类恩诺沙星0.2mg/L.各抗菌药物添加回收率范围均在64.0%～107.7%,变异系数均小于15%.假阴性结果显示,除青霉素(5%)和氨苄青霉素(4%)出现假阴性外,红霉素、庆大霉素、新霉素、恩诺沙星和金霉素均未出现假阴性.与国外同类试剂盒比较,结果显示两者对10种抗菌药物的检测限一致.     

TTC法检测牛奶中的抗菌药物

针对用TTC法检测牛奶抗菌药物残留过程中因为在被检乳样中加入指示菌的数量不稳定而影响检测的问题,本研究增设了菌液稀释度试验以确定加入的菌液量。同时,采用TTC法对奶牛场常用的几种抗菌药物检测其在乳中的最低检测浓度。结果是青霉素3μg/kg,链霉素660μg/kg,庆大霉素620μg/kg,卡那霉素6200μg/kg,红霉素30μg/kg,环丙沙星500μg/kg,土霉素100μg/kg,金霉素100μg/kg,磺胺嘧啶100μg/kg。本研究用TTC法对青霉素、红霉素、土霉素、金霉素和磺胺嘧啶的检测灵敏度均达到农业部规定的牛乳中兽药残留最高限量要求。TTC法具有简便、价廉的优点,并且所检测的抗菌素范围较广,符合我国奶牛场中使用抗菌药物种类较多的现状。     

猪组织中4种药物残留规律研究

试验采用高效液相色谱法检测猪组织(肌肉、肝和肾)中的金霉素、土霉素、磺胺二甲嘧啶和喹乙醇残留量,通过对饲料中4种药物添加量和组织中残留量的分析,研究其残留规律.结果表明,在药物的添加范围内,猪组织中磺胺二甲嘧啶的残留规律为肝＞肾＞肌肉;金霉素的残留规律为肾＞肝＞肌肉;土霉素的残留规律为肝＞肾＞肌肉;喹乙醇的残留规律为肝＞肾＞肌肉.     

烟酸诺氟沙星在猪,鸡体内的组织残留研究

本文报道了烟酸诺氟沙星在猪、鸡体内的组织残留研究结果，猪、鸡均按１０ｍｇ／ｇ剂量给药，采用ＨＰＬＣ法测定肝、肾、肌肉中诺氟沙星浓度。猪肌注给药后７２小时，肾。肌肉中药物浓度已低于仪器最低检测限（０．０５μｇ／ｇ），肝中仍能检出少量药物，浓度为０．３０５±０．１６９μｇ／ｇ；鸡口服给药后４８小时，肝、肾、肌肉中药物浓度均已低于最低检测限。根据本试验结果，建议猪、鸡使用烟酸诺氟沙星后休药期为６天和２天。     

恩诺沙星在猪组织中残留消除规律研究

在常规饲养条件下,对健康猪按2.5 mg/kg体重的剂量肌肉注射2.5%恩诺沙星注射液,每日2次,连续注射3 d.停药后第2、4、6、8、10、12、14天分别屠宰4头猪.分别采取每头猪的肌肉(注射部位)、脂肪(腹脂)、肝和肾脏等4种组织,用高效液相色谱法进行残留量测定.结果表明:残留在肌肉、脂肪组织中的药物消除较快,第8天总残留量(恩诺沙星 环丙沙星)已下降至检测限(20μg/kg)以下;肝和肾脏组织中的药物消除缓慢,第14天测得猪肾中药物总残留量为40μg/kg.     

恩诺沙星微囊制剂在猪体内残留消除规律研究

采用高效液相色谱法研究恩诺沙星微囊制剂在猪体内各组织中的残留消除规律。恩诺沙星微囊制剂混饲,连续给药7 d,宰杀猪,取组织。组织样品经磷酸盐缓冲液提取,C18固相萃取柱净化,过膜,用流动相:0.05 mol/L磷酸溶液/三乙胺-乙腈(82+18)溶解,微孔过滤,进行HPLC分析。结果表明,当样品浓度为0.02～1μg/g时,线性关系良好。该法最低检测限为20μg/kg,回收率在72%～90%之间,变异系数小于10%。残留在肌肉、脂肪中的恩诺沙星和环丙沙星消除较快,第5天总残留量已下降至检测限以下;肝和肾脏中的残留药物消除较缓慢,第7天肾中药物总残留量为91.48μg/kg。综合各组织中总残留量和MRL规定,建议恩诺沙星微囊制剂休药期为7 d。     

纯牛奶中抗菌药物残留的检测

为了解山西省交城县各大超市销售纯牛奶中抗菌药物残留情况，随机采购此牛奶50份，分别用TTC法、微生物检测法和酶标免疫分析法进行抗生素残留检测。TTC法检测出阳性率为8％，可疑率为6％；微生物法检测出青霉素类残留阳性率为10％。酶标免疫分析法检测出四环素类阳性率为8％；链霉素残留阳性率为22％；磺胺二甲嘧啶检测全部为阴性。结果表明，交城县各大超市售纯牛奶中有部分存在抗菌药物残留。     

断乳仔猪腹泻药物的防治效果试验

选择32日龄断乳的健康仔猪120头,分为4组,进行腹泻药物预防效果试验,分别为利高霉素组,庆大霉素、阿莫西林组,恩诺沙星、阿莫西林组,金霉素＋阿莫西林组;同时,再选用庆大霉素,磺胺嘧啶＋地塞米松,恩诺沙星进行药物治疗试验。结果表明,金霉素、阿莫西林组预防效果最佳（仔猪下痢预防有效率为71．7％）,其次是恩诺沙星、阿莫西林组（预防有效率57.2％）;而在3种治疗药物中,以庆大霉素治愈率最高（94.3％）,其次为恩诺沙星（84．0％）和磺胺嘧啶＋地塞米松（77.3％）。     

五种抗菌药物从猪、鸡饲料至有机肥中的药物残留迁移规律研究

为研究抗菌药物从饲料向畜禽粪肥转移的残留迁移规律,将40头猪和200羽鸡分为饲喂组和空白对照组进行饲喂对照实验和粪便堆肥发酵实验,其中空白对照组使用普通全价饲料,饲喂组在饲料中加入盐酸金霉素50 mg/kg、磷酸泰乐菌素50 mg/kg、磺胺对甲氧嘧啶各50 mg/kg、恩诺沙星150 mg/kg、二甲氧苄啶10 mg/kg,每日及时对各组实验动物粪便进行采集,样品经提取和净化后使用液相色谱-串联质谱进行分析定量。所得结果表明,猪、鸡饲喂含多种抗生素饲料后粪便中可以检出抗菌药物原型,其可能进入有机肥料发酵制作的环节。参照猪、鸡粪便中排出抗菌药物含量峰值建立模型对发酵期间粪肥中抗菌药物含量进行采样测定,结果显示,恩诺沙星、泰乐菌素和二甲氧苄啶在堆肥过程中会由于温度升高和氧化作用发生降解,其半衰期在5周左右,到10周后其含量低于检测限;但金霉素和磺胺对甲氧嘧啶被少量降解,残留迁移风险较高。     

猪、牛、鱼组织中四环素类药物残留的测定

以本实验室研制的四环素类药物多残留检测试剂盒为基础，建立了猪、牛、鱼组织中四环素、土霉素、金霉素和多西环素4种药物残留的酶联免疫检测方法。该方法在猪、牛、鱼组织中的检测限均低于13μg/kg，4种四环素类药物最高残留限量浓度添加回收率范围为47．5％～119．4％，批内、批间变异系数在25％以内。检测各种组织中四环素类药物的临界值分别为猪肉49．2μg／kg、猪肝138．7μg／kg、牛肉52．1μg／kg、牛肝124．4μg／kg、鱼肉44．1μg／kg。     

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.