阿莫西林残留ELISA检测试剂盒质量验证

为了对用于检测牛奶中阿莫西林残留的酶联免疫吸附试验(ELISA)检测试剂盒进行质量验证,试验采用不同梯度浓度的方法进行研究。结果表明:阿莫西林标准品浓度在0.5~13.5μg/L范围内具有较好线性关系,50%竞争抑制浓度为2.0μg/L,试剂盒对牛奶中阿莫西林的最低检测限为4.6μg/L。牛奶中分别添加5.0,10.0μg/L的阿莫西林标准品,回收率在72.2%~108.7%之间,批内变异系数小于8.9%,批间变异系数小于11.9%;试剂盒可在37℃条件下保存7 d,可同时检测牛奶中阿莫西林、青霉素、氨苄西林、萘夫西林等药物的残留总量。与仪器方法进行实际样品检测相比,ELISA方法检测结果具有良好的可信度。     

UPLC-MS/MS检测牛奶中头孢哌酮代谢消除规律研究

本文建立了超高效液相色谱-串联质谱法检测牛奶中头孢哌酮的浓度,并对其在血液中残留消除进行研究。样品经过乙腈提取、氮吹、HLB柱净化后,经Acquity UPLC BEH Shield RP18(100 mm×2.1 mm,1.7μm)分离,以乙腈和0.02%甲酸水为流动相,采用多反应监测模式,方法的最低定量限低于2.0μg/L,在2.0~100μg/L浓度范围内线性良好,相关系数0.9938,通过2、20、100μg/L浓度的加标回收实验表明,回收率在75.8%~94.6%之间,RSD%在2.43%~8.95%之间,满足于牛奶中头孢哌酮类药物残留检测要求;结果表明静脉注射给药后头孢哌酮在6 h内牛奶中药物含量即可达到峰值,60 h左右牛奶中药物残留消除到低于检测限。     

超高效液相色谱-串联质谱测定牛奶及血清中头孢哌酮残留及消除规律研究

为了建立超高效液相色谱-串联质谱(UPLC-MS/MS)检测牛奶及血清中头孢哌酮的浓度,并对其在牛奶及血清中残留消除进行研究,样品经乙腈提取净化后,以乙腈和0.1%甲酸水为流动相,采用Acquity UPLC BEH Shield RP18(100 mm×2.1 mm,1.7μm)色谱柱,通过多反应监测模式进行检测。结果表明:该方法的最低定量限低于2.0μg/L,在2.0~100.0μg/L浓度范围内线性良好,相关系数均大于0.99。2.0,20.0,100.0μg/L浓度的加标回收试验结果表明,回收率在72.8%~93.6%之间,相对标准偏差(RSD)在1.93%~9.75%之间,方法满足牛奶及血清中头孢哌酮类药物残留检测要求。通过静脉注射给药,不同时间范围采集牛奶及血清样本进行检测,给药后头孢哌酮在0.5 h内血药浓度即可达到峰值,48 h左右原药代谢低于检测限;在6 h内牛奶中药物含量即可达到峰值,60 h左右牛奶中药物残留消除到低于检测限。     

高效毛细管电泳法测定兽用注射用青霉素钾的含量

研究测定兽用注射用青霉素钾含量的高效毛细管电泳方法,优化了高效毛细管电泳法检测青霉素的电泳条件,缓冲液为pH7.8（6mol/LHCL调节）的30mmol/L硼砂溶液,在分离电压为18kV、温度为25℃条件下青霉素峰形尖锐,浓度与峰面积在40-200μg/mL范围内线性良好,相关系数为0.9971,回收率范围为99.3%-101.5%,日内及日间变异系数均小于4%。     

高效液相色谱荧光检测法测定牛奶中4种氟喹诺酮类药物残留

为了建立一种同时测定牛奶中4种氟喹诺酮类药物(恩诺沙星、环丙沙星、沙拉沙星、二氟沙星)多残留高效液相色谱检测方法,将牛奶中的残留药物用磷酸-甲醇溶液重复提取2次,正己烷除去脂肪净化后浓缩,流动相溶解后用高效液相色谱-荧光检测器测定。结果表明,4种氟喹诺酮类药物在0.01~1.00μg/mL浓度范围内具有良好的线性关系(R=0.999 9),在0.01,0.05,0.10,0.50μg/mL和1.00μg/mL 5个浓度添加水平上,平均回收率为77%~93%,样品的批内和批间变异系数均值分别为5.29%和7.83%,定量限均为10 ng/mL。环丙沙星、恩诺沙星、沙拉沙星检测限均为5 ng/mL,二氟沙星检测限为8 ng/mL。本研究建立的检测方法简单、快速、灵敏度和回收率高,适用于牛奶中4种氟喹诺酮类药物残留检测。     

液相色谱-串联质谱法检测牛奶中林可胺类与大环内酯类药物

牛奶食品中林可胺类药物残留可引起肾功能障碍和革兰氏阳性菌的耐药性增加;大环内酯类药物残留可引起过敏反应和导致携带耐药因子的菌株扩散。本试验利用液相色谱-串联质谱法检测牛奶中林可胺类与大环内酯类药物残留。牛奶样品中的残留药物用乙腈提取后,用正己烷去除脂肪等杂质,浓缩后供液相色谱-串联质谱法测定。经试验:系列浓度范围内呈现良好的线性关系,相关系数(R2)均大于0.990,方法的回收率为70%~120%,批内、批间相对标准偏差均小于20%。检测限为1μg/kg,定量限为2.5μg/kg。     

牛奶中粘菌素和杆菌肽残留的固相萃取超高效液相色谱-串联质谱法测定

建立了牛奶中粘菌素和杆菌肽药物残留的固相萃取-超高效液相色谱-串联质谱测定方法,样品用4%三氯乙酸乙腈溶液提取,经乙醚除脂,HLB固相萃取柱净化,相色谱-串联质谱法分析,外标法定量。结果表明：粘菌素和杆菌肽在20~2 000μg/L浓度范围内呈现良好线性,R2均大于0.998;方法检出限为5μg/kg,定量限为10μg/kg;粘菌素和杆菌肽分别在10~100μg/kg和10~1 000μg/kg浓度添加范围内的平均回收率为84%~110%,批内、批间RSD均小于20%。该方法具有简便快捷、灵敏度高、定性准确等优点,能够满足牛奶中其残留检测有关法规的要求。     

QuEChERS-高效液相色谱法检测牛肉中的阿维菌素类药物残留

旨在建立牛肉组织中阿维菌素、伊维菌素、多拉菌素和甲氨基阿维菌素等4种阿维菌素类药物残留的QuEChERS-高效液相色谱检测方法。牛肉组织样品搅碎后,乙腈两次提取,QuEChERS净化,氮气吹干,含1-甲基咪唑和三氟乙酸酐的乙腈溶液衍生化,高效液相色谱-荧光检测器检测(激发波长365nm,发射波长475nm)。在0.1μg/mL~2μg/mL范围内4种药物均呈线性相关,相关系数大于0.999。检测限为2μg/kg(S/N=3),当添加浓度为2、10、40μg/kg时,4种药物的平均回收率在77.3%~97.2%,日内相对标准偏差为2.05%~4.91%(n=5),日间相对标准偏差为0.27%~1.64%(n=3)。建立的方法简便、灵敏、高效、安全,可用于动物组织中阿维菌素类药物残留的检测。     

分光光度法检测牛奶中的磺胺类药物残留

本文研究了分光光度法在检测牛奶中磺胺类药物残留中的应用效果。结果表明,用对—二甲氨基苯甲醛作显色剂,测定的最佳条件:波长为454nm,比色皿厚度为0.5cm,显色剂用量为1.5mL;测定浓度在3～15μg/mL范围内均与工作曲线有良好的线性比例关系,平均回收率为94.2%,变异系数为1.73,变异系数≤5,说明分光光度法测定牛奶中磺胺类药物残留的方法可行,回收率高。     

QuEChERS-液相色谱串联质谱法测定动物源性食品中氟喹诺酮类残留量

建立了用QuEChERS-液相色谱串联质谱法测定禽肉、禽蛋和牛奶中15种氟喹诺酮类药物残留的检测方法。样品经酸化乙腈提取后,经QuEChERS试剂净化,液相色谱串联质谱测定,内标法定量。结果表明,牛奶和禽肉的检出限为2.0 ng/g,定量限为4.0 ng/g,禽蛋的检出限为3.0 ng/g,定量限为4.0 ng/g。在2.0~100 ng/mL的添加浓度范围内线性良好,线性相关系数(r)大于0.995,牛奶、禽肉以及禽蛋三种基质在添加浓度为4.0~50.0 ng/g范围时,回收率为61%~105.2%,批内、批间精密度均小于15%。该方法简便、快速、准确,适用于大批量动物源性样品中氟喹诺酮的快速检测。     

白术、微米白术和白术多糖对断奶仔猪生长性能和肠道形态及微生态区系的影响

试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。     

Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia

Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.     

Y‐chromosomal variation of local goat breeds of Turkey close to the domestication centre

Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.     

A brief history of the prevention of infectious diseases by immunisations

Infectious diseases have always been a terrible scourge for humans. The appearance of these plagues, as they were called without distinction, was generally connected to various conditions: asters, climatic changes or religious reasons. The concept of contagious, and then infectious, diseases came slowly. Variolation, i.e. transmission of ‘virulent’ matter to induce a natural disease and the immunity against it, was brought from Constantinople to England by Lady Montague, in 1721. This ‘variolation’ technique was also often performed in veterinary medicine against diseases like sheep-pox or pleuropneumonia. As ‘vaccination’ is the term generally accepted for ‘immunisation’, variolation can be the word designating such a technique. The second period of the history of immunisation began, in 1880, with the studies of Pasteur and his collaborators. A great number of bacterial vaccines were developed: dead, live but attenuated or only parts of pathogens. The viruses were produced in animals, then in eggs and at last, in tissue cultures. Second generation vaccines appeared with genetic engineering: recombinant vaccines, vector vaccines, nucleic acids vaccines, and markers vaccines, among others. These novel technologies can permit the development of new ones and improve the quality of the vaccines already existing.     

Micronutrient Content of Certain Tropical Conventional and Unconventional Feed Resources of Southern India

The ash, silica and certain important micronutrients were estimated in conventional and unconventional feed and fodder resources available in Southern India. Commonly used dry roughages, such as paddy straw, ragi straw, maize kadbi/stalk, jowar kadbi/stalk, bajra stalk and wheat straw, were high in ash (9.9% +/- 0.77%) and silica (6.4% +/- 0.65%) and low in most of the other micronutrients, except iron, with paddy straw containing most silica (>9%). Cultivated non-leguminous (maize, jowar) and improved green crops (hybrid napier, guinea, green panic, NB-21, CO-1) were also high in ash (10.5% +/- 0.60% and 12.5% +/- 0.51%) but were moderate sources of P, Mg and Cu and good sources of Zn (98 +/- 13.8 ppm and 55 +/- 6.7 ppm). Leguminous green fodders (stylosanthus, lucerne, cow pea, soyabean) were excellent sources of Ca (1.9% +/- 0.16%), Mg (0.40% +/- 0.05%), Cu (30 +/- 5.2 ppm), Zn (121 +/- 14.7 ppm) and Fe (1234 +/- 166 ppm) and moderate sources of P. Mixed local grasses and weeds were high in silica (6.9% +/- 1.00%) but were good sources of Cu, Zn and Fe. Cereal grains (maize, wheat, rice, ragi) were low in ash (2.9% +/- 0.33%) and were relatively poor sources of Ca (0.22% +/- 0.03%), Mg (0.19% +/- 0.03%) and Cu (13 +/- 3.1 ppm). Pulses were low to medium sources of most minerals and good sources of Fe (1230 +/- 293 ppm). Oil seed cake/extractions (groundnut cake, cotton seed cake, soyabean meal, sunflower cake, safflower cake) and cereal by-products (rice polish, rice bran, wheat bran) were excellent sources of P (1.1% +/- 0.47% and 2.3% +/- 0.19%) and good sources of Zn (65 +/- 3.9 ppm and 66 +/- 10.7 ppm) and Fe (938 +/- 130 ppm and 662 +/- 126 ppm). Among the unconventional feeds screened, orange peel, sunflower heads, meat meal, rubber seed cake, spirulina algae and sea weeds contained plentiful Ca, Zn and Fe: tree leaves/top feeds (mulberry, erythrina, glyricidia, banana, subabul, groundnut haulms) were excellent sources of Ca (1.5% +/- 0.13%), Zn (120 +/- 22.9 ppm) and Fe (1033 +/- 133 ppm) but relatively poor sources of P. Soyabean husk, cocoa seed husk, rubber seed cake and meat meal were moderate to good sources of P (1.0% and 0.33%). The high Zn and Fe values of most feeds/fodders were probably due to soil contamination. This account of the micronutrient content of feed/fodder resources should help in strategic supplementation intended to alleviate local deficiencies.     

Feline intracranial neoplasia: retrospective review of 160 cases (1985-2001)

The purpose of this study was to determine the frequency of different tumor types within a large cohort of cats with intracranial neoplasia and to attempt to correlate signalment, tumor size and location, and survival time for each tumor. Medical records of 160 cats with confirmed intracranial neoplasia evaluated between 1985 and 2001 were reviewed. Parameters evaluated included age, sex, breed, FeLV/FIV status, clinical signs, duration of signs, number of tumors, tumor location(s), imaging results, treatment, survival times, and histopathologic diagnosis. Most of the cats were older (11.3 +/- 3.8 years). Primary tumors accounted for 70.6% of cases. Metastasis and direct extension of secondary tumors accounted for only 5.6 and 3.8% of cases, respectively. Twelve cats (7.5%) had 2 or more discrete tumors of the same type, whereas 16 cats (10.0%) had 2 different types of intracranial tumors. The most common tumor types were meningioma (n = 93, 58.1%), lymphoma (n = 23, 14.4%), pituitary tumors (n = 14, 8.8%), and gliomas (n = 12, 7.5%). The most common neurological signs were altered consciousness (n = 42, 26.2%), circling (n = 36, 22.5%), and seizures (n = 36, 22.5%). Cats without specific neurological signs were common (n = 34, 21.2%). The tumor was considered an incidental finding in 30 (18.8%) cats. In addition to expected relationships (eg, meninges and meningioma, pituitary and pituitary tumors), we found that lesion location was predictive of tumor type with diffuse cerebral or brainstem involvement predictive of lymphoma and third ventricle involvement predictive of meningioma.     

Bovine Mastitis in Selected Areas of Southern Ethiopia

A study on bovine mastitis, designed to determine the causal agents, prevalence of infection and impact of risk factors in three cattle breeds, was conducted in selected areas of southern Ethiopia. A total of 307 lactating and non-lactating cows, of which 162 were indigenous Zebu, 85 Jersey and 60 Holstein-Friesian, were examined by clinical examination and the California mastitis (CMT) test. Of these, 40.4% were positive by CMT and bacteriology for clinical or subclinical mastitis, with prevalence rates of 37.1% and 62.9%, respectively. Out of 1133 quarters examined, 212 (18.7%) were found to be infected, 83 (39.2%) clinically and 129 (60.8%) subclinically. The prevalence of mastitis was significantly higher in Holstein-Friesian than in indigenous Zebu, in non-lactating cows than in lactating cows, in the early lactation stage than in the mid-lactation stage, in cows with lesions and/or tick infestation on skin of udder and/or teats than in cows without this factor, and in the wet season than in the dry season. Mastitis increased with parity number (R = 0.9). Of 248 CMT and clinically positive udder quarter samples analysed microbiologically, 212 were culturally positive for known mastitis pathogens and 36 were negative. Of the 199 positive samples, Staphylococcus accounted for 39.2%, Streptococcus for 23.6%, coliforms for 14.1%, Micrococcus and Bacillus species for 8.0% each and Actinomyces or Arcanobacterium (Corynebacterium) for 7.0%. It was concluded that there was a high prevalence of clinical and subclinical mastitis, mainly caused by Staphylococcus aureus, Streptococcus agalactiae and Escherichia coli, in this study area.     

不同日粮氮水平对山羊氮代谢和微生物蛋白质合成的影响

本试验旨在探讨不同日粮氮水平对内蒙古白绒山羊氮代谢和微生物蛋白质合成(MCP)的影响,以达到提高氮利用率,减少环境污染和饲料资源的浪费。试验选用9只体况良好、体重为(43.83±2.95)kg,装有瘤胃瘘管的内蒙古白绒山羊,按体重随机分为3组,每组3只。日粮分为低氮7.5%、中氮10.5%、高氮13.5%3个氮水平。试验使用常规试验方法分析测定粪尿血液等生化指标,通过全收尿法和尿嘌呤衍生物法估测MCP。结果表明:随着氮水平增加,氨氮(NH3-N)浓度、氮摄入量、尿氮排出、尿中尿素氮(UUN)和MCP显著增加(P0.05),干物质采食量(DMI)显著降低(P0.01);沉积氮占总摄入氮的比例在中氮组最高,MCP在高氮组最高。综上所述,适当降低日粮氮水平可减少粪尿氮排放,提高反刍动物氮利用率。     

Microsporidial keratopathy in two dogs

A microsporidial keratopathy is described in two dogs. Both dogs presented with a unilateral stromal keratopathy characterized by multifocal coalescing opacities, and the diagnosis was made on histopathologic examination of keratectomy specimens. Transmission electron microscopy (TEM) on formalin‐fixed, paraffin‐embedded corneal tissue was performed in one dog, and the morphologic features were consistent with Nosema species infection. Both dogs were initially diagnosed and treated by superficial keratectomy. One dog received additional antifungal medication and underwent a penetrating keratoplasty following local recurrence two years later. No other systemic lesions attributable to the microsporidial infection were identified clinically. The clinical and diagnostic pathology findings, treatment, and follow‐up are discussed.