乳房炎牛奶中复方阿莫西林纳米乳的残留检测及消除试验     

杨雪峰  姜金庆  孙红武  欧阳五庆 《兽医大学学报》2012,(8):1212-1216

利用高效液相色谱仪建立复方阿莫西林纳米乳（AMX-LH-NE）在牛奶中的残留监控高效液相色谱法（HPLC）,并通过残留消除试验,研究AMX-LH-NE在乳房炎牛奶中的残留消除规律,确定其弃奶期。结果显示,阿莫西林（AMX）和盐酸左氧氟沙星（LH）分别在7.5～400μg/L和40～600μg/L线性关系良好;平均回收率为（99.72±1.46）%和（99.65±1.53）%;相对标准偏差（relative standard deviation,RSD）为1.46%和1.54%;平均保留时间为（11.59±0.21）min和（6.87±0.02）min;日内精密度RSD为1.59%和1.39%,日间精密度RSD为3.17%和3.29%。在乳房炎牛奶中,AMX和LH的残留量均随着休药时间的延长而迅速降低;AMX的弃奶期为停药后35.96h,LH的弃奶期为停药后32.94h。结果表明,所建立的HPLC方法专属性好,回收率、重复性和精密度高,可为牛奶中AMX-LH-NE的残留监控提供检测方法;利用此检测方法确定的AMX-LH-NE的弃奶期为停药后36h。  相似文献   

Prevalence,clinical presentation,prognosis, and outcome of 17 dogs with spinal shock and acute thoracolumbar spinal cord disease          下载免费PDF全文

Amanda M. Full DACVIM  DVM  Heidi L. Barnes Heller DVM  DACVIM  Miyu Mercier DVM  DACVIM 《Journal of Veterinary Emergency and Critical Care》2016,26(3):412-418

  相似文献   

Increasing feed withdrawal and lairage times prior to slaughter decreases the gastrointestinal tract weight but favours the growth of cecal Enterobacteriaceae in pigs     

S. Martín-Pelez  S.M. Martín-Orúe  J.F. Prez  E. Fbrega  J. Tibau  J. Gasa 《Livestock Science》2008,119(1-3):70-76

The objective of this study was to evaluate the influence of different feed withdrawal and lairage times prior to slaughter on the gastrointestinal tract (GIT) weight and on the fermentation pattern and numbers of Enterobacteriaceae in the cecum of pigs. A total of 72 finishing pigs (6 pens, 12 animals each) were included in the study and were sent to the slaughterhouse on three consecutive days. On each day pigs from two pens were deprived of feed for either 2 or 12 h before leaving the farm. Pigs from each of the two pens were divided in sub-groups (4 pigs each) on the moment of loading onto the truck and followed the same distribution at the slaughterhouse. Once there, each sub-group corresponding to the same feed withdrawal time was held in different holding pens for 0, 5 or 10 h before slaughter. The weight of the gastro-intestinal tract (GIT) was determined and cecal content was collected to evaluate pH, short chain fatty acids (SCFA) and ammonia (NH₃) concentrations as well as lactobacilli and Enterobacteriaceae numbers. Total GIT weight decreased as feed withdrawal (P < 0.0001) and lairage time (P < 0.001) increased within a range between 6.69 and 4.59 kg. Cecal pH increased with feed withdrawal (P < 0.0001) and lairage time (P = 0.0001) (ranging from 5.79 to 6.79) in parallel to a decrease in the total SCFA concentration (P < 0.005) (from 211 to 100 mM). The percentages of acetic and propionic acid were not modified by the experimental treatments but significant decreases were registered in the percentage of butyric acid with the increased times of both withdrawal (P < 0.0001) and lairage (P < 0.005). The percentage of valeric and branched SCFA and also NH₃ concentration showed an increase with withdrawal (P < 0.005, P < 0.0001 and P < 0.005 respectively) and lairage (P < 0.005, P < 0.0001 and P < 0.001 respectively). Lactobacilli numbers decreased as lairage time increased (from 9.97 to 8.63 log 16S rRNA gene copies/g FM; P < 0.05) and Enterobacteriaceae numbers increased with both, feed withdrawal (P < 0.05) and lairage (P < 0.05) (ranging from 8.53 to 9.95 log 16S rRNA gene copies/g FM).The previous to slaughter increase in feed withdrawal and lairage times decreased the GIT weight but involved changes in the gut microbial ecosystem caused through changes in the fermentation pattern that lead to the increase of Enterobacteriaceae numbers. This increase could represent a higher risk of carcass contamination by the enteropathogens of this group such as Salmonella. However this potential risk should be further investigated.  相似文献   

Influence of sudden changes in management program on physiological and behavioral parameters in hens     

Ashraf M. KHALIL  Kanji MATSUI  Ken-ichi TAKEDA 《Animal Science Journal》2004,75(3):253-259

The present study was designed to test the effects of sudden changes of food access and light duration on the physiological and behavioral parameters of hens. The physiological parameters investigated were heart rate (HR), body temperature (BT), and locomotor activity (LA) using a radiotelemetry system. After implantation of the telemetry transmitters, six hens were housed individually in cages under constant environmental conditions for 10 days with a photoperiod of 15 h light (04.00–19.00 hours), and food was available ad libitum at all times. After that, the same hens were subjected to a feed withdrawal trial, from 12.00 to 08.30 hours, followed by a lighting hour reduction trial by changing the time of lights‐off from 19.00 to 14.00 hours. The physiological and behavioral data were recorded for 2 days before each trial, as control data. With the feed withdrawal trial, during the light and dark periods, HR and BT were significantly lower in the hens without food access than in the control. Whereas, LA was significantly lower only during the light period in the hens without food access than in the control. Further, the time spent resting increased significantly, but the time spent feeding decreased significantly in the hens without food access than in the control. Also, the number of times the cage was pecked and pecking of the feeder occured at a significantly higher level, while the number of times beaks were wiped occured at a significantly lower level in the hens without food access than in the control. With the lighting hour reduction trial, during the light period, HR and BT were significantly higher, whereas LA was significantly lower in the ’sudden light‐off’ treated hens than in the control. In addition, during the dark period, HR, BT and LA were significantly higher in the sudden light‐off treated hens than in the control. Moreover, in the sudden light‐off treated hens, the time spent preening and feeding decreased significantly, but the time spent resting increased significantly than in the control. It is concluded that sudden changes in a management program might result in many significant differences as were found in the physiological and behavioral parameters of hens in the present study.  相似文献   

How to extrapolate a withdrawal time from an EHSLC published detection time: A Monte Carlo simulation appraisal     

P.‐L. TOUTAIN 《Equine veterinary journal》2010,42(3):248-254

Reason for performing study: For legitimate medications, veterinarians must advise the owners or trainers of horses on appropriate withholding times after a treatment, to avoid the risk of incurring a positive drug test. Objective: To explore the safety span to select that a veterinarian may extrapolate a tailored withdrawal time (WT) from a generic detection time (DT) as published by the European Horserace Scientific Liaison Committee (EHSLC). Methods: Using Monte Carlo simulations, it was shown that for a low variability of pharmacokinetic parameters (CV = 20%), an uncertainty span of about 40% may be selected to transform a mean DT into a WT (i.e. WT = 1.4 DT), which covers 90% of the horse population. In contrast for a highly variable drug (CV = 40%), an uncertainty factor of about 2.1–2.2 needs to be selected, i.e. a WT that is twice the DT. Results: The relative impact of the different factors of variability on the final WT was documented by a so‐called sensitivity analysis. It was shown that the parameters that have the greatest influence on the value of a DT are those that control the terminal half‐life of the drug disposition. In contrast, parameters controlling the level of urine (or plasma) concentrations (i.e. the actual administered dose, the urine‐to‐plasma ratio and the bioavailability) collectively have a minimal influence on the DT. Conclusions and potential relevance: In practice, this means that the main sources of uncertainty are of biological origin and cannot be reduced by any managerial options. The influence of the number of experimental horses that are used by EHSLC to establish a DT was shown that with the standard EHLSC protocol of 6 horses, half of the trials lead to a proposed DT that is equal to or higher than the population 90^th percentile. Increasing the number of investigated horses to 8 and 10 would increase this last probability to 85 and 90%, respectively.  相似文献   

土霉素在黄颡鱼肌肉组织中残留消除规律的研究   总被引：1，自引：1，他引：0  

袁娟李汝琴  彭小云刘红陈孝煊  吴志新 《中国农学通报》2013,29(23):27-31

为研究土霉素在黄颡鱼肌肉组织中残留消除规律。在水温25℃条件下,以每天100 mg/kg 的剂量,连续5天口灌土霉素后定时取样,采用高效液相色谱法检测。结果显示：黄颡鱼肌肉组织中土霉素的平均回收率为80.2%,方法检出限为0.05 μg/g。研究结果表明：土霉素在黄颡鱼肌肉组织中消除缓慢,其含量降到0.1 μg/g的休药期为46天。  相似文献   

Effect of Mitragyna speciosa aqueous extract on ethanol withdrawal symptoms in mice     

Kumarnsit E  Keawpradub N  Nuankaew W 《Fitoterapia》2007,78(3):182-185

Administration of the aqueous extract of Mitragyna speciosa at a dose of 300 mg/kg significantly inhibited ethanol withdrawal-induced behaviors that included rearing, displacement and head weaving. The results also showed that at doses of 100, 300 and 500 mg/kg M. speciosa showed antidepressant activity without effect on the spontaneous motor activity.  相似文献   

基于Meta分析的宅基地退出影响因素研究     

周丽  高强 《安徽农业大学学报》2024,33(2):60-72

由于区域选择、模型方法、测量方式等研究设计的不同,学界关于宅基地退出影响因素的研究结论存在不同程度的差异。运用Meta分析方法,以期准确识别农户宅基地退出的影响因素及其效应,推动有条件的农户自愿有序退出宅基地。研究发现:农户宅基地退出受到农村推力与城镇拉力的正向影响及农村拉力的负向影响,而城镇推力未产生显著影响。从影响强度看,家庭经济条件改善是推动农户宅基地退出的主要动力,家庭结构压力是阻碍农户宅基地退出的关键因素。在影响因素的异质性上,中部和西部地区宅基地面积的影响比东部地区强,文化水平和宅基地宗数在研究退出意愿的文献中影响更强,性别因素在出版质量更高的文献中影响更强。随时间推移,农户年龄的影响趋向加强,文化水平的影响趋向减弱,家庭年总收入的影响趋于稳定。为此,应注重构建公平合理的退出补偿机制及完善退出后农户的社会保障机制,促进农村宅基地退出政策完善和研究发展。  相似文献   

Evaluating effects of water withdrawals and impoundments on fish assemblages in southern New England streams,USA     

Y. KANNO  J. C. VOKOUN 《Fisheries Management and Ecology》2010,17(3):272-283

Abstract Balancing aquatic conservation and water supply is becoming a major global issue for urban landscapes. The purpose of this study was to evaluate the ecological effects of stream‐flow alterations via water withdrawals and impoundments on fish assemblage structure. Electric fishing data were collected at 33 wadeable streams in Connecticut, located in the Southern New England region of USA. Fish sampling was conducted directly downstream of water withdrawals for municipal and agricultural water supply, and study sites differed in potential water withdrawal rates and the presence of impoundments. Regression analysis showed that water withdrawal rate was more important than other natural and anthropogenic factors (e.g. landcover and stream size) in explaining several fish assemblage metrics. Stream sites with high withdrawal rates were generally characterised by lower proportions of fluvial dependent fishes (fish which need flowing water to complete a portion of their life history) and benthic invertivores (fish which feed on bottom‐dwelling stream insects in riffle habitat), and had a greater percent composition of macrohabitat generalists, particularly members of the family Centrarchidae. Some assemblage metrics responded linearly with increasing magnitude of water withdrawals, but others were non‐linear. Results are consistent with ecological theory that alteration of the natural flow regime will impact stream biota.  相似文献   

恩诺沙星可溶性粉在白羽乌骨鸡组织中残留消除规律研究     

余军军  谢焕龙  宁军  韦田  孙石开 《畜牧兽医科学(电子版)》2021,(5):8-9,12

为研究恩诺沙星可溶性粉在乌骨鸡体内的残留消除规律。50只11日龄健康白羽乌骨鸡,随机分为2组,给药组40只,对照组10只,给药组混饮恩诺沙星水溶液,浓度为75 mg/L,2次/d,连续用药5 d,对照组不给任何抗菌药物,与给药组同环境饲养。在最后一次给药后9、20、40、70、106 d采集肌肉、肝脏、肾脏、皮脂等样本,经LC-MS/MS法测定组织中的恩诺沙星及环丙沙星残留量,并利用WT1.4软件计算休药期。恩诺沙星可溶性粉在乌骨鸡肌肉、肝脏、肾脏及皮脂中的休药期分别是102.48、0、41.93、116.38 d。为保证消费者健康和食品安全,推荐恩诺沙星可溶性粉在乌骨鸡体内的休药期应大于117 d。  相似文献