超高效液相色谱-静电轨道阱质谱正负切换同时筛查定量饲料中的51种农药残留化合物

建立了超高效液相色谱-静电轨道阱质谱法检测饲料中的51种农药残留物的检测方法和目标化合物的质谱数据库。饲料样品经0.1 mol/mL HCl : 甲醇=1:3提取,高速离心,经稀释后进样分析。采用Thermo Syncronis C18色谱柱(150 mm×2.1 mm, 3 μm)作为固定相,0.1 %甲酸和0.1%甲酸乙腈作为流动相进行梯度洗脱。质谱采用正负切换离子扫描,一对母离子和子离子的精确质量数进行定性,以母离子的响应强度积分面积进行定量分析。51种农药残留化合物在最优化条件下分离良好,在定量范围内均线性良好(线性相关系数r≥0.99),回收率也可达到50.61 ％～ 109.49 % ,相对标准偏差(RSD)小于9.1 %。本方法具有简便、快速、灵敏、准确等特点,适用于饲料中同时筛查和定量农药残留化合物。     

超高效液相色谱-四级杆-静电场轨道阱高分辨质谱法筛查测定饲料中16种硝基咪唑类药物

建立了基于超高效液相色谱-四级杆-静电场轨道阱高分辨质谱联用(UPLC-Q-Exactive Orbitrap)快速筛查和确证定量饲料中16种硝基咪唑类药物的分析方法。饲料样品经含0.1%甲酸的乙腈-水(80:20,V/V)溶液震荡提取,Waters ACQUITY UPLC○R BEH C18色谱柱(2.1mm×100mm,1.7μm)分离,以(含0.1%甲酸)乙腈-甲醇(50:50,V/V)溶液和(含0.1%甲酸)水溶液为流动相进行梯度洗脱。静电场轨道阱全扫描得到16种硝基咪唑类药物的一级精确质量数与理论精确质量数对比,质量偏差在0.04975~0.93988mDa;同时建立了二级质谱数据库,实现对16种硝基咪唑类药物的定性筛查及同步定量。16种硝基咪唑类药物在0.1~200μg/L浓度范围内线性关系良好r>0.9990,方法检测限在25μg/Kg^100μg/Kg,回收率在49.47%~105.4%。     

HPLC法检测饲料中4种硝基呋喃类药物

时饲料中四种硝基呋喃类药物呋喃西林(NFZ)、呋喃妥因(NFT)、呋喃它酮(FTD)和呋喃唑酮(FZD)的高效液相色谱(HPLC)检测方法进行了研究.采用50 mL乙腈于65℃下超声提取药物.经MCX固相萃取小柱净化后进行液相色谱-紫外检测,检测波长为370 nm对饲料进行10～500μg/g硝基呋喃类药物的添加回收实验,结果表明,4种药物的平均回收率为80.6%～99.9%(n=4),日内变异系数为0.68%～8.99%(n=4),日间变异系数为1.85%～8.44%(n=3).配合饲料中NFZ、NFT、FTD、FZD的检测限分别90、69、56μg/g和148 μg/g,定量限分别为180、137、112μg/g和296 μg/g;预混合饲料中NFZ、NFT、FTD、FZD的检测限分别为59、132、66μg/g和88 μg/g,定量限分别118、265、132μg/g和176μg/g.     

超高效液相色谱-串联四级杆质谱法测定水产品中硝基呋喃类代谢物的方法改进

以GB/T 20752-2006中的实验方法为基础,对超高效液相色谱-串联质谱法(UPLCMS/MS)检测水产品中呋喃它酮(AMOZ)、呋喃西林(SEM)、呋喃妥因(AHD)和呋喃唑酮(AOZ)4种硝基呋喃代谢物的样品前处理方法进行了改进。试样用0. 2 mol/L盐酸溶液溶解后,经2-硝基苯甲醛衍生化,加入0. 1 mol/L磷酸氢二钾,混匀后用1 mol/L氢氧化钠溶液调节pH约为7. 4。经乙酸乙酯直接振荡离心提取上清液,氮气吹干经超高效液相色谱串联质谱,采用正离子多反应监测(MRM)模式检测,同位素内标法定量。结果表明,四种代谢物回收率控制在90%～120%之间,RSD10%。实际样品分析结果显示,新的样品前处理方法简单、分析时间短、结果可靠,适合水产品中硝基呋喃代谢物残留的测定。     

检测饲料中4种硝基呋喃类药物的简易高效液相色谱法

本文建立了一种同时检测饲料中呋喃唑酮、呋喃西林、呋喃妥因、呋喃它酮等4种硝基呋喃类药物的高效液相色谱法(HPLC-UV)。以乙腈:0.01 mol/L乙酸钠缓冲液(2/8)为流动相,检测波长375 nm,4种药物的保留时间均在15 min之内。样品提取过程简便,饲料样品以乙腈在80℃加热条件下提取,过滤膜后HPLC检测,整个过程在20 min内完成。该法对4种药物在饲料中的检测限为16~50μg/kg,4种药物在空白饲料中的添加回收率为80.1%~93.5%。因此,该方法可以用作饲料中硝基呋喃类药物的常规检测方法。     

QuEChERS-超高效液相色谱-串联质谱法同时测定蜂蜜、蜂王浆中硝基呋喃类代谢物残留

通过优化QuEChERS前处理方法并结合超高效液相色谱-串联质谱(UPLC-MS/MS)技术建立了蜂蜜、蜂王浆中硝基呋喃类代谢物残留的检测方法。样品经盐酸和2-硝基苯甲醛水解衍生,使用乙腈提取,以Waters净化管作为基质提取液净化剂,采用电喷雾电离正离子(ESI~+)、多反应监测(RM)模式检测,外标法定量。实验结果表明,蜂蜜和蜂王浆在1～100ng/ml范围内,4种硝基呋喃类代谢物的线性相关系数(r)0.999,检出限分别为0.1～0.5μg/kg、0.3～0.5μg/kg。蜂蜜中3个添加水平的回收率范围为95.2%～101.7%(n=6),相对标准偏差(RSD)为0.8%～4.1%;蜂王浆中3个添加水平的回收率范围为99.2%～103.5%(n=6),相对标准偏差为0.9%～2.1%。该方法快速简便、净化效果好、灵敏度高、准确度好,可以满足对蜂蜜、蜂王浆中硝基呋喃类代谢物同时检测的要求。     

反相高效液相色谱法同时测定饲料中的10种性激素

本文建立了饲料中10种性激素(己烯雌酚、雌二醇、戊酸雌二醇、苯甲酸雌二醇、炔雌醇、醋酸氯地孕酮、左炔诺孕酮、炔诺酮、氯烯雌醚、炔雌醚等)的反相高效液相色谱检测方法。饲料样品经乙腈提取后,用固相萃取法进行净化。液相色谱采用Shim-pack VP-ODS色谱柱(250mm×4.6mm,5μm),以乙腈和水为流动相进行梯度洗脱,流速1.0mL/min,230nm和280nm双波长检测,柱温30℃。10种性激素线性关系良好,相关系数均大于0.9998,添加回收率为95.32%～102.5%,RSD1.8%。该方法简便、准确、专属性好,可作为饲料中违禁性激素的检测方法。     

超高效液相色谱串联质谱法测定饲料中31种药物同时添加研究

本研究建立了检测饲料中31种药物（5种受体激动剂、9种磺胺、8种喹诺酮、2种氯霉素、4种大环内酯、3种硝基咪唑）的超高效液相色谱串联质谱方法。样品经80%乙腈-水（含0.1%甲酸）提取，PRIMEHLB固相萃取柱净化，以0.1%甲酸水-乙腈（正离子模式）和水-乙腈（负离子模式）为流动相进行梯度洗脱，C18色谱柱（2.1 mm×50 mm,1.7μm）分离，多反应监测模式进行检测，外标法定量。结果表明，31种药物在1～50μg/ml范围内线性关系良好，相关系数大于0.99。添加水平分别0.5、2.5和5.0μg/kg时，回收率范围分别为72.9%～107.8%、81.5%～108.1%和81.2%～107%。本方法检测灵敏度高，操作简单，可为饲料监管提高方法参考。     

液相色谱-电喷雾质谱联用检测蜂蜜中四种硝基呋喃类代谢物

介绍了高效液相色谱电喷雾多级质谱(LC/MSn) 同时快速、准确测定蜂蜜中呋喃西林、呋喃唑酮、呋喃它酮和呋喃妥英4种硝基呋喃类抗生素代谢物。硝基呋喃类代谢物在酸性条件下经过邻硝基苯甲醛衍生化, 液相萃取后经色谱分离, 利用二级质谱进行定性和定量。加标样品平均回收率达到64% ~79%, 定量下限(LOQ) 为0 1~1μg·kg-1, 检测限(LOD) 达到0 05~0 5μg·kg-1。该方法测定结果满足欧盟(EU)对进口动物源性食品中硝基呋喃类抗生素的残留要求。     

超高效液相色谱-串联质谱测定畜禽肉中硝基呋喃代谢物方法关于pH值的优化探讨

本试验的目的是优化畜禽肉中硝基呋喃代谢物超高效液相色谱-串联质谱测定方法。样品经洗涤后去除杂质,在酸性条件下水解,与加入的2-硝基苯甲醛溶液进行衍生化反应,反应产物调pH7.6后经乙酸乙酯提取,氮气吹干,5%乙腈含0.1%甲酸水溶液溶解残余物,用超高效液相色谱-串联质谱仪测定。四种硝基呋喃代谢物内标的使用补偿了前处理过程对最后定量结果的影响,结果准确可靠。     

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.     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -     

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

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.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Changes in proportion of canine urinary calculi composed of calcium oxalate or struvite in specimens analyzed from 1981 through 2001

The objective of this report was to characterize 20-year changes in proportion of calcium oxalate (CaOx) calculi and struvite calculi in dogs, and associations with breed, age, and sex. In this retrospective study, results of analysis of urinary calculi from dogs were reviewed for specimens received between July 1, 1981, and December 31, 2001. Breed, sex, age, year of submission of the specimen, and mineral type(s) were analyzed statistically. CaOx or Struvite or both were contained in 18,966 of 20,884 (91%) specimens. For both sexes, a 20-year statistically significant increase was observed in the proportion of calculus specimens that contained CaOx. The increase in this proportion was greater in females (1% to 31%) than in males (18% to 82%). From 1998 to 2001, when proportions may have plateaued, the odds of specimens containing CaOx were markedly higher in 18 breeds, markedly lower in 5 breeds, and not significantly different in 13 breeds compared with crossbreds. For both sexes, a 20-year statistically significant decrease was observed in the proportion of calculus specimens that contained struvite. This decrease in proportion was greater for males (79-16%) than for females (97-68%). From 1998 to 2001, when proportions plateaued, the odds of calculi containing struvite were markedly lower in 20 breeds, markedly higher in 1 breed, and not significantly different in 15 breeds when compared with crossbreds. Breed, age, and sex were associated statistically with CaOx or struvite urolithiasis. In conclusion, there appears to have been a long-term increase in the proportion of specimens of canine urinary calculi that contain CaOx as well as a long-term decrease in the proportion of specimens of calculi that contain struvite for both male and female dogs. The rate of change appeared to begin leveling off in the period 1998 to 2001. The recent proportion of dogs with either CaOx- or struvite-associated urolithiasis may depend on breed, age, and sex, and on interactions among these 3 factors.     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.