固相萃取-气相色谱法测定饲料中13种有机氯农药残留量

建立了饲料中13种有机氯类农药残留的固相萃取-毛细管气相色谱(SPE-CGC)分析方法。以丙酮-正己烷混合物作提取剂,采用超声波提取样品,然后用固相萃取柱净化提取物。采用OV-1701毛细管气相色谱柱分离样品,电子捕获检测器(ECD)。有机氯农药的平均回收率:83.76%～106.22%,RSD为1.46%～5.72%,检出限:0.00039～0.00352μg/ml。结论:该法简便快速、灵敏准确,可广泛应用于饲料中有机氯农药的检测。     

牛奶中有机磷农药残留的气相色谱法测定

提出同时测定牛奶中敌百虫、甲胺磷、敌敌畏、马拉硫磷、倍硫磷五种有机磷农药残留的检测方法。在选定的色谱条件下,添加浓度在0.5～10.0μg/mL之间时5种农药的检测限分别为0.031μg/mL、0.013μg/mL、0.023μg/mL、0.019μg/mL和0.014μg/mL,回收率范围分别达81.0%～85.5%、84.5%～89.4%、79.0%～81.8%、77.3%～82.5%和77.9%～89.5%,变异系数在0.29%～3.96%之间。本方法对牛奶中有机磷农药残留的检测分析准确可靠。     

超高效液相色谱-串联质谱法测定鸡组织中氯苯胍残留

研究建立了鸡组织中氯苯胍残留的超高效液相色谱-串联质谱检测方法。样品经酸化乙腈提取后,分别经中性氧化铝柱和HLB固相萃取柱净化,C₁₈柱分离,超高效液相色谱-串联质谱测定,外标法定量。氯苯胍在10 ng/mL～500 ng/mL的浓度范围内呈线性相关,相关系数为0.994以上。本方法对氯苯胍在鸡组织中的检测限为5μg/kg,定量限为10μg/kg;鸡肉、鸡肝和鸡肾在添加50μg/kg～200μg/kg浓度范围内,其回收率为76.7%～107.6%,鸡脂肪和鸡皮在添加100μg/kg～400μg/kg浓度范围内, 其回收率为81.2%～106.8%, 批内变异系数均在1.4%～19.5%之间,批间变异系数在2.5%～12.8%之间。本方法快速、灵敏、重现性好,各项技术指标均满足国内外相关法规要求,适用于鸡组织中氯苯胍的残留检测。     

气相色谱法测定禽蛋中有机氯农药和多氯联苯残留量

建立了同时测定禽蛋中14种有机氯农药(OCPs)和7种多氯联苯(PCBs)的气相色谱法。样品用乙腈超声提取,浓硫酸净化,气相色谱法测定,外标法定量。21种待测化合物在5～200μg/L时线性关系良好,方法定量限为0.3～0.7μg/kg,在5、20、100μg/kg三个加标水平下,鸡蛋空白样品的平均加标回收率为75.1%～103.8%,相对标准偏差为1.41%～6.64%。本法简便、快速、准确、成本低廉,适用于禽蛋中多种有机氯农药和多氯联苯的快速筛查。     

饲料中己烯雌酚ELISA检测方法的建立

为了建立一种饲料中己烯雌酚(DES)残留的检测方法,试验采用酶联免疫吸附试验(ELISA)进行检测,并对该方法的检测限、准确度、精密度和特异性等参数进行考察。结果表明:本试剂盒的线性工作范围为0.1~8.1μg/kg,IC50浓度为0.417μg/kg,对饲料中DES的检测限为5μg/kg;对饲料样品中DES的添加回收率范围为83%~107%,批内变异系数≤5.7%,批间变异系数≤6.3%;与DES类似物无交叉反应。本研究所建立的ELISA检测方法具有简单、灵敏、准确等特点,适用于饲料中DES残留的快速检测。     

超高效液相色谱-串联质谱法测定牧草中22种农药残留

试验采用QuEChERS前处理方法结合超高效液相色谱串联质谱（UPLC-MS/MS）建立牧草中22种农药残留分析检测方法。结果表明,22种农药在0.5～20μg/L范围内线性关系良好（R2＞0.994）,检出限（LODs）为0.01～0.2μg/kg,定量限（LOQs）为0.02～0.5μg/kg。在2.5、5、10μg/kg三个不同浓度水平下,回收率为73.7%～107.1%,相对标准偏差为0.7%～9.8%。该方法线性关系良好,检出限低,回收率高,适用于牧草中22种农药的定性定量分析。 [关键词]牧草|超高效液相色谱串联质谱|QuEChERS|农药残留     

液相色谱法测定猪组织中阿维菌素类药物残留量

动物组织中残留的阿维菌素、依维菌素和多拉菌素经乙腈提取,碱性氧化铝固相萃取柱净化后,与荧光衍生化试剂反应,产物用高效液相色谱(荧光检测器)进行检测,实现了阿维菌素类药物的残留分析.本方法在猪组织中测定阿维菌素类药物的检测限为1μg/kg;在猪组织中添加浓度为1、2、5μg/kg时的回收率为55%～75%.     

凝胶渗透色谱净化—气相色谱法测定奶油中有机氯农药残留

作者采用凝胶渗透色谱（GPC）对奶油中8种有机氯农药进行样品前处理,气相色谱—电子捕获检测器进行测定,以保留时间定性,峰面积定量。在10~800 ng/mL浓度范围内,8种有机氯农药的线性良好,相关系数在0.9981~0.9996,回收率在92.4%～117.0%,RSD在1.83%～7.92%,方法检出限为0.65~2.33 μg/kg,满足奶油中有机氯农药残留检测要求。     

鸡皮脂和肾脏中替米考星残留HPLC检测方法的建立

本试验旨在建立鸡皮脂和肾脏组织中替米考星残留量的HPLC测定方法。皮脂和肾脏组织中残留的替米考星用乙腈提取、MCX固相萃取柱净化,采用高效液相色谱-紫外检测法测定。皮脂组织和肾脏组织中替米考星检测限分别为20μg/kg和30μg/kg,定量限分别为35μg/kg和50μg/kg。空白皮脂组织添加替米考星在35～150μg/kg浓度水平,回收率在75%～98%之间,批内与批间变异系数均小于10%;空白肾脏组织添加替米考星在50～500μg/kg浓度水平,回收率在71%～97%之间,批内变异系数小于11%,批间变异系数小于10%。本试验建立的方法快速、准确、灵敏,适用于鸡皮脂和肾脏组织中替米考星残留量的检测。     

酶联免疫法测定猪肉中磺胺类药物的残留

利用酶联免疫法对猪肉中的磺胺类药物残留进行检测,结果表明:该方法的灵敏度为1μg/L,最低检测限为1.5μg/kg;向空白样本中添加浓度为100、200μg/kg磺胺标准品时,平均回收率范围为76.1%～101.7%,变异系数为4.6%～11.9%;利用该方法与液相色谱-串联质谱法检测实际样本,其阴、阳性判断结果一致。该法灵敏准确、重复性好、特异性高,适用于对猪肉中15种磺胺类药物进行多残留检测。     

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.     

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.     

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.     

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.     

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.     

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.