河南省牧场生鲜乳中黄曲霉毒素M_1本底含量的研究分析

为了全面掌握河南省牧场生鲜乳中黄曲霉毒素M_1含量总体状况,选取河南省具有代表性的45家牧场,用液相色谱串联质谱法对牧场生鲜乳大罐样中黄曲霉毒素M_1残留进行测定,确定其大致范围。结果表明:被检测的45家牧场生鲜乳中黄曲霉毒素M1含量大致范围为0~0.124μg/kg,平均值为0.039μg/kg,多数牧场生鲜乳黄曲霉毒素M_1含量集中在0.02~0.06μg/kg。由于目前国家标准规定生鲜乳中黄曲霉毒素M1最大残留量为0.5μg/kg,本试验数据说明河南省牧场生鲜乳中黄曲霉毒素M1含量均符合国家规定,但个别牧场生鲜乳中黄曲霉素M_1含量稍高。本研究可为河南省生鲜乳中黄曲霉毒素M_1含量的安全性研究提供基础数据,为牧场生鲜乳生产环节及时调整防护措施提供参考,同时也为消费者提供相关信息。     

液相色谱-质谱/质谱法检测生鲜乳中雌二醇方法的建立

为了建立生鲜乳中17β-雌二醇的液相色谱-质谱/质谱检测方法,试验采用甲醇提取生鲜乳样品后,经固相萃取柱富集净化,采用液相色谱-质谱/质谱法测定,外标法定量。结果表明:17β-雌二醇在1~50 ng/mL浓度范围内线性关系良好,相关系数为0. 998 3,建立方法的检测限为0. 15μg/kg,定量限为0. 50μg/kg;在1~10 ng/mL加标浓度范围内,方法的回收率为76. 1%~99. 8%,相对标准偏差≤9. 7%。本试验建立方法的样品处理比较简单,使用等度洗脱,提高了方法的灵敏度,明显降低了检测限和定量限,提高了方法的准确度。本试验建立的方法适用于实验室检测牧场生鲜乳中17β-雌二醇残留。     

雌激素质谱筛查分析方法的研究

试验建立了雌二醇、雌三醇、雌酮、炔雌酮、苯甲酸雌二醇、己烯雌酚、己二烯雌酚和染料木素等8种激素的多残留高效液相色谱-串联质谱的检测方法,确定了质谱条件、色谱条件和样品前处理方法。在0.5~50.0 ng/ml范围内有良好的线性关系,相关系数R20.99,方法的检出限(LOD)为0.005 ng/ml,定量限(LOQ)为0.01 ng/ml。在0.05~1.0μg/kg的添加水平上,8种雌激素的平均回收率在67.2%~103.4%之间,相对标准偏差在0.39%~5.97%之间。该方法重现性好,实验结果准确度高,可适用于对生鲜乳和饲料中激素类物质进行摸底排查。     

生鲜乳中皮革水解蛋白快速检测方法的建立

本研究依据卫生部指定的《乳与乳制品中动物水解蛋白鉴定方法》,对该方法的检测步骤和所用仪器进行了优化,建立了生鲜乳中皮革水解蛋白的酶标快速检测方法。试验结果表明,浓度在50~250μg/g范围内的阳性添加回收率为72.0%~89.2%;含量为100μg/g时的重复性验证的RSD值为2.9%。应用该方法对陕西省的11批生鲜乳与卫生部指定方法进行了比对试验,结果表明两种方法检测结果相同。与其他方法相比,该方法操作简单、成本低、污染少,检测速度快,适用于质检单位和乳品企业对生鲜乳中皮革水解蛋白的快速检测。     

高效液相色谱-质谱/质谱法检测生鲜乳中孕酮残留量方法的建立和优化

为了建立生鲜乳中孕酮的高效液相色谱-质谱/质谱检测方法,试验采用生鲜乳样品经甲醇溶液提取后,用C_(18)固相萃取柱净化后,再经电喷雾离子源高效液相色谱-质谱/质谱测定,保留时间和选择离子丰度比定性,外标法定量。结果表明:孕酮在0.1~5.0 ng/mL浓度范围内呈良好线性相关,相关系数为0.999 9,建立方法的检出限为0.02μg/kg,定量限为0.04μg/kg,在0.1~5.0 ng/m L加标浓度范围内,方法的回收率为79.6%~105.1%,相对标准偏差≤8.9%。与行业标准相比,试验建立方法的检出限和定量限明显降低,增强了方法灵敏度,适用于牧场生鲜乳中孕酮残留的检测。     

HPLC法同时测定牛羊肉中4种雌激素的残留量

为了建立高效液相色谱法(HPLC法)同时测定牛羊肉中己烯雌酚、雌二醇、苯甲酸雌二醇和戊酸雌二醇残留量的方法,试验将样品用甲醇2次超声、离心,提取液浓缩后经0.45μm有机滤膜过滤,利用HPLC法进行测定。结果表明:4种组分分离良好,并得到浓度与峰面积成正比的工作曲线,相关系数达到0.999以上,精密度(CV)良好(CV≤0.80),回收率范围为85.96%~101.56%。     

离子色谱法测定生鲜乳中的硫氰酸根

本实验通过对离子色谱条件进行优化,建立了离子色谱法测定生鲜乳中硫氰酸根的检测方法。浓度在0.1~5.0 mg/L,硫氰酸根标准曲线的线性相关系数为0.9993,方法检出限为1.3μg/L,定量限为4.2μg/L。对样品进行加标回收实验,硫氰酸根的回收率为95%~104%,RSD为0.9%~1.5%(n=6),该方法简单可靠,重现性好,适用于生鲜乳中硫氰酸根的检测。     

雌二醇单克隆抗体制备及间接竞争ELISA检测方法的建立

为建立敏感、特异、快速的雌二醇（estradiol,E₂）残留免疫检测方法,本研究利用雌二醇人工抗原（E₂-BSA）免疫BALB/c小鼠,应用淋巴细胞杂交瘤技术制备特异性雌二醇单克隆抗体,利用高效价、高特异性单克隆抗体建立间接竞争ELISA（icELISA）方法。结果显示,试验成功筛选获得一株稳定分泌抗雌二醇抗体的杂交瘤细胞株（3H3）,抗体效价可达1∶320 000,利用3H3腹水抗体优化间接竞争icELISA反应条件,检测抗体的敏感度,IC₅₀为1.636 ng/mL,IC₂₀~IC₈₀线性范围为0.202~13.281 ng/mL。雌二醇腹水抗体与雌三醇、乙炔雌二醇的交叉反应率分别达0.31%和0.25%,而与雌酮、戊酸雌二醇、苯甲酸雌二醇、炔雌醚、己烯雌酚、壬基酚的交叉反应率均<0.1%。结果表明,利用本研究制备的单克隆抗体建立雌二醇间接竞争ELISA检测方法,可满足食品中雌二醇残留高灵敏度的检测要求。     

国产苜蓿添加量对当地生鲜乳营养品质的影响研究

国产苜蓿供应当地的奶牛养殖场具有明显的价格优势,但是目前合理且切实可行的苜蓿添加量及其对生鲜乳营养品质的影响仍缺乏科学的研究。本试验以黑龙江省大庆市种植的苜蓿为原料,在当地9个规模化奶牛养殖场开展了为期一年的苜蓿饲喂试验,分析苜蓿不同添加量对生鲜乳品质的影响。结果显示,与未添加苜蓿的养殖场相比,添加3 kg/d国产苜蓿不能显著改善生鲜乳中的营养成分（P＞0.05）。当日粮中苜蓿添加量达到6 kg/d时,生鲜乳中粗蛋白质（CP）及干物质（DM）含量显著提高（P＜0.05）,但对脂肪及乳糖含量无显著影响（P＞0.05）。且能够显著增加不饱和脂肪酸的含量（P＜0.05）,改善生鲜乳的脂肪酸组成。说明将各养殖场目前常采用的3 kg/d添加量提高到6 kg/d有助于改善生鲜乳的营养品质。     

利用荧光定量技术检测生鲜乳中黄曲霉毒素M_1

本试验利用荧光定量检测技术检测生鲜乳中黄曲霉毒素M_1,最低检出限为0.047μg/L;取空白生鲜乳样品按0.05μg/L、0.1μg/L黄曲霉毒素M_1标准品进行添加,回收率均在90.00%～110.00%之间。各添加浓度批内、批间变异系数均低于15%;用该黄曲霉毒素M_1荧光定量检测卡和仪器法分别对50份生鲜乳盲样进行测定,结果全部相符,提示该法简便快捷、检测结果可靠,可用于黄曲霉毒素M_1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.     

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.     

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.