猪肉组织中四环素类药物残留检测——高效液相色谱-串联质谱法研究

建立了猪肉组织中四环素类药物残留检测的高效液相色谱-串联质谱方法.色谱条件为色谱柱为XBridge C18柱(150 mm×2.1 mm,5 μm),流动相为0.3%甲酸乙腈溶液 0.3%甲酸水溶液;柱温 20 ℃,流速0.2 mL/min;进样量20 μL.质谱条件为电喷雾离子源(ESI );多反应监测(MRM)方式采集.外标法定量.结果表明,四环素、土霉素和金霉素在10～400 ng/mL浓度范围内呈现良好线性,相关指数R2均大于0.999;方法检测限为5 ng/g,定量限为10 ng/g.50、100和200 ng/g三个添加浓度的平均回收率为72.3%～94.6%,批内批间RSD均小于20%.     

高效液相色谱法测定猪组织中维吉尼亚霉素M1的残留

建立了猪组织中维吉尼亚霉素M1残留的高效液相色谱测定方法.样品用甲醇-0.2mol/L NH4H2PO4溶液提取,正己烷洗涤,经C18固相萃取柱净化后做HPLC分析.选用二极管矩阵检测器,波长245 nm;色谱柱为ODS-3 C18柱(4.6 mm×250mm,5 μm);流动相为乙腈-水(37.5:62.5,V/V).维吉尼亚霉素M1标准曲线线性范围在0.1～2.0 μg/mL.对不同组织的3种加药浓度进行回收率测定,回收率在72%～85%,变异系数在10%以内.最低检测限为10 ng/g.     

高效液相色谱－串联质谱法检测猪肝组织中氯霉素残留的研究

建立了猪肝组织中氯霉素残留检测的高效液相色谱-串联质谱(LC-MS/MS)法.液相色谱条件为色谱柱为Alltech Altima C18柱(150 mm×3.2 mm,5 μm);流动相为甲醇-水(1∶ 1,V/V);柱温为30 ℃;流速为0.3 mL/min;进样量为20 μL.质谱条件为电喷雾离子源(ESI-),多反应离子监测(MRM)方式进行采集;监测离子质荷比为320.60＞52.20,320.60＞194.15.以氯霉素的同分异构体间位氯霉素作内标,内标法定量.结果表明,氯霉素的线性范围为0.5～10 ng/mL,相关系数R2＝0.999 9;方法检测限为0.1 μg/kg,定量限为0.2 μg/kg;从0.1、0.2、0.4和1.0 μg/kg四个添加浓度检测结果可以看出,方法的平均回收率为96.6%～116.6%(n＝6),批内批间RSD均小于20%.     

鸡蛋和鸡肉中尼卡巴嗪残留检测高效液相色谱 串联质谱法研究

建立了鸡蛋和鸡肉中尼卡巴嗪残留标示物4,4'-二硝基碳酰替苯胺(DNC)检测的高效液相色谱-串联质谱方法(HPLC-MS/MS).液相色谱条件为色谱柱为XBridge C18柱(150 mm×2.1 mm,5 μm),流动相为甲醇 0.1 mol/L的乙酸铵水溶液(75 25,V/V),柱温30 ℃,流速0.2 mL/min,进样量20 μL.质谱条件为电喷雾离子源(ESI-),多反应监测(MRM)方式进行采集;DNC-D8同位素内标法定量.结果表明,DNC在10～500 ng/mL浓度范围内呈现良好的线性关系,R2为0.999 7;鸡蛋和鸡肉中DNC残留检测方法检测限均为0.5 ng/g,定量限均为1 ng/g;鸡蛋中从2、5和10 ng/g三个添加浓度检测结果可以看出,方法平均回收率为95.9%～102.2%,批内RSD为0.9%～4.4%,批间RSD为0.3%～2.1%.鸡肉组织从100、200和300 ng/g三个添加浓度检测结果可以看出,方法平均回收率为94.0%～103.3%,批内RSD为2.0%～6.3%,批间RSD为3.1%～5.2%.     

超高效液相色谱串联质谱法测定饲料中大观霉素的研究

实验建立了测定饲料中大观霉素的超高效液相色谱串联质谱方法。样品以甲醇草酸溶液(80∶20,V/V)提取后经ACQUITY UPLC Hilic C18柱(2.1 m×50 mm,1.7μm)分离,在选定质谱条件下进行检测,外标法定量。结果表明,大观霉素浓度在0.2～10μg/mL时与峰面积呈良好的线性关系,相关系数均大于0.999,平均回收率为64.10%～98.54%,批内变异系数为5.54%～15.10%,批间变异系数为2.92%～11.89%。     

液相色谱-质谱联用分析饲料中新型的β2-肾上腺素能激动剂——齐帕特罗

建立了饲料中齐帕特罗的液相色谱-质谱联用(LC-MS)检测方法.液相色谱条件为Waters AntantisTM C18色谱柱(150 mm×2.1 mm,3μm);柱温30℃;流动相为乙腈-0.2%甲酸(892,V/V);流速0.2 mL/min;进样量20μL.质谱条件为电喷雾离子源(ESI+),选择离子监测质荷比(m/z)为262、244、202、185带正电荷的准分子离子和碎片离子.齐帕特罗的线性范围为0.01～4μg/mL,最低定量检测限0.01μg/g,回收率为(90±10)%.     

超高效液相色谱-串联质谱法测定饲料中的己烯雌酚

本文建立了饲料中己烯雌酚的高效液相色谱—串联质谱检测方法(UPLC-MS/MS)。色谱条件:色谱柱为ACQUITY UPLC BEH C18柱2.1mm×50mm1.7μm;流动相为乙腈—水(50:50,v/v),流速0.2mL/min;进样体积10μL;柱温35℃。采用负电喷雾离子源,在多反应监测(MRM)模式下进行分析,外标法定量,3对定性离子对分别为:m/z320.90151.85、320.90256.92和320.90193.90,定量离子对为320.90151.85。在0.1～500μg/L浓度范围内呈良好的线性,相关系数r0.999。在1、5、20mg/kg3个添加水平,平均回收率75.2%～97.6%,日内变异系数在2.1%～6.3%之间,日间变异系数在3.2%～9.7%,检测限为10μg/kg。     

HPLC法测定中兽药散剂中非法添加的10种磺胺类药物

建立了中兽药散剂中非法添加10种磺胺类药物测定的高效液相色谱方法。液相色谱条件为:色谱柱C_(18)柱150 mm×4.6 mm(i.d.),5μm;流动相:乙腈-甲醇-2%乙酸溶液(15+5+80);流速:1.0 mL/min;柱温:30℃;检测波长:270 nm;进样量10μL。结果表明,10种磺胺类药物在50~800 ng/mL浓度范围内呈现良好线性关系,相关系数R~2均大于0.995,方法检测限为5μg/g,从5、10和20 mg/g 3个添加浓度检测结果可以看出,方法平均回收率为85.4%~106.8%(n=6),批内批间RSD均小于10%。     

高效液相-串联质谱法测定蜂蜜中利巴韦林残留研究

本研究采用同位素内标法建立了蜂蜜中利巴韦林残留液相色谱-串联质谱方法。样品经提取后经混合型阳离子交换固相萃取净化后上机测定,色谱柱为Hypercarb多孔石墨碳色谱柱(100 mm×2.1 mm,5μm),以0.1%(V/V)甲酸甲醇-0.1%(V/V)甲酸水为流动相进行梯度洗脱,采用电喷雾正离子(ESI⁺)和多反应监测(MRM)模式测定,同位素内标法定量。结果显示,利巴韦林进样浓度在2～100 ng/mL浓度范围内呈良好的线性关系(R²=0.9995);方法检出限和定量限分别为1μg/kg和2μg/kg;2、4、20μg/kg三个添加水平下,回收率在67.6%～112.7%之间,批内、批间相对标准偏差均小于15%。本方法简便、准确、快速、灵敏,适用于蜂蜜中利巴韦林残留检测。     

犬血浆中非罗考昔高效液相色谱检测方法的建立

建立测定犬血浆中非罗考昔含量的高效液相色谱方法。以蛋白沉淀法处理血样，流动相为乙腈∶0.025%三氟乙酸(V∶V)=51∶49，检测波长为290 nm，柱温35℃，流速为1 mL/min，进样量为50μL，经ZORBAX Stable Bond-C₁₈(4.6 mm×150.0 mm,5μm)色谱柱分离，进行色谱分析。结果显示，本方法专属性良好，非罗考昔的血浆浓度在0.05～4.00μg/mL内线性关系良好，检测限为0.025μg/mL，定量限为0.050μg/mL，验证样品的回收率为81.81%～114.26%，批内变异系数在7.74%以下，批间平均变异系数在11.68%以下。本方法简单、准确、快速，可用于犬血浆中非罗考昔的检测分析以及该药物的药动学和相对生物利用度等研究。     

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.     

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.     

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.     

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.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

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.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.