超微量DNA模板扩增鉴定绵羊早期胚胎性别体系优化

本实验旨在运用超微量胚胎DNA模板扩增SRY基因鉴定绵羊早期胚胎性别PCR体系和方法优化.根据绵羊Y染色体性别决定SRY基因的723 bp的保守序列设计引物,析因法建立巢式PCR体系,联合扩增SRY和GAPDH基因,经绵羊静脉血液和胚胎超微量DNA样本调整测试灵敏度后,切割40枚绵羊桑椹胚的少量胚细胞进行性别鉴定,并对...     

采用血液、羽毛等材料鉴别鸡性别PCR方法的应用研究

公母鸡染色体上的染色体螺旋蛋白基因(chromobox-he-licase-DNA binding gene,CHD 1基因)的内含子基因序列存在差异,通过PCR方法可扩增该基因内含子的保守序列,可对鸡等非平胸禽类的性别进行鉴定。本研究首先采集42只28日龄肉鸡抗凝血,完成血液DNA PCR鉴定性别,结果表明,42只商品肉鸡中22只公鸡、20只母鸡,与剖检结果相同;其次,采集20只90日龄SPF鸡(13只公鸡、7只母鸡)和15只2日龄SPF鸡的抗凝血和羽毛,完成其DNA的PCR鉴定以及与微量血的PCR检测结果的比较。结果表明,90日龄、2日龄SPF鸡的微量血PCR与抗凝血、羽毛提取DNA的PCR鉴定结果均相同,其中,90日龄SPF鸡与其外观性别完全吻合;另外,采集12枚15日龄鸡胚的尿囊液、羽毛、肌肉,提取DNA后PCR方法可扩增出区分性别的特异性条带,鉴定结果一致,12枚15日龄鸡胚中均为7个雄性、5个雌性。本研究表明,微量血PCR和血液、羽毛等材料提取DNA后的PCR方法均可准确快速鉴定鸡和鸡胚的性别,可作为家禽育种过程中常规鉴定方法的有力补充,适合大型养殖场规模化鉴定,也满足科研领域区分鸡和鸡胚性别的需求。     

鸡与鹌鹑属间杂交早期胚胎性别鉴定体系的建立与优化

研究参考鹌鹑Wpkci和β-actin基因设计引物,采用RT-PCR技术,旨在建立鉴定鸡(♂)与鹌鹑(♀)杂交后代早期胚胎性别的方法。Wpkci引物扩增已知性别鹌鹑及未知性别杂交种胚胎的cDNA,从母禽胚胎获得402bp和296bp两条特异性条带,而公禽没有得到条带。为进一步验证该鉴定体系的可靠性和稳定性,采用了多重PCR从母禽胚胎获得490bp、402bp、296bp三条特异性条带,而公禽只有490bp的内标条带。在对试验关键因素进行优化的基础上,建立了简单、快速、可靠、稳定的鉴定杂交种早期胚胎性别的方法。     

实时荧光定量PCR检测H1N1亚型猪流感病毒

根据GenBank中H1N1亚型猪流感病毒NP基因的序列（DQ889686）,利用Premier express设计并合成1对引物和相应的TaqMan探针,从猪流感病毒HN407株接种的鸡胚尿囊液中提取总RNA,经RT-PCR扩增NP基因。将鉴定正确的NP基因片段克隆入pGEM-T Easy载体中,转化大肠杆菌JM109,经PCR及测序鉴定后得到阳性重组质粒。以该阳性重组质粒为荧光定量PCR标准品模板建立标准曲线。对探针浓度、引物浓度、镁离子浓度和退火温度进行优化,建立了最佳的荧光定量PCR反应体系和扩增程序。经临床应用表明荧光定量PCR的建立为早期诊断猪流感病毒、定量分析猪流感病毒感染程度奠定了基础。     

兔早期胚胎PCR性别鉴定体系的建立

根据兔SRY基因序列设计两对引物作为兔雄性特异性引物,根据兔APP基因序列设计1对引物作为内标引物,分别建立了兔早期胚胎性别鉴定的双重PCR和巢式PCR反应体系,在不同浓度的基因组DNA和兔早期胚胎上进行性别鉴定应用,同时,对兔SRY巢式PCR引物特异性进行了分析。结果表明,多重PCR扩增兔基因组DNA可以准确判定其性别,扩增灵敏度为100pg基因组DNA;多重PCR鉴定24枚兔32细胞桑椹胚性别,只能对整胚成功鉴定。巢式PCR,公兔基因组DNA扩增出282bp的SRY基因片段,母兔没有扩增产物,扩增灵敏度为10pg;对24枚兔32细胞桑椹胚性别鉴定结果表明,巢式PCR可以对少至4个胚胎细胞进行准确鉴定,同一胚胎结果符合率为100%(24/24)。SRY引物只对兔雄性基因组DNA特异,而其他动物(人、牛、绵羊、小鼠)雄性DNA及兔的冲卵液,均无PCR产物。     

鸡胚致死孤儿病毒荧光定量PCR检测方法的建立及初步应用

目的:建立鸡胚致死孤儿病毒CELO的荧光定量PCR检测方法,实现该病毒在鸡胚及禽源性生物制品中的快速检测.方法根据CELO L5纤突1序列设计引物和探针,建立荧光定量PCR检测方法,并对其线性、特异性、精密性、灵敏度进行考察.运用建立的方法对40份SPF鸡胚尿囊液和16株流感疫苗主种子批毒种进行CELO检测.结果:建立的荧光定量PCR其最佳线性范围为1x109~1x104拷贝/μl,R2值达0.99以上,特异性良好,与其他种属的腺病毒及流感病毒间均无交叉反应,灵敏度为102拷贝/μl;荧光定量PCR方法检测40份SPF鸡胚尿囊液和16株流感毒种结果为阴性.结论:本研究所建立的鸡胚致死孤儿病毒荧光定量PCR检测方法,特异性好,敏感性高,为鸡胚及禽源性生物制品中的快速检测提供了技术支撑.     

间接ELISA法鉴定鸭胚性别

为开发一种新型高效的鸭胚性别鉴定方法,采集不同品种孵化14~24 d鸭胚尿囊液,包被酶标板,利用间接ELISA法测定鸭胚尿囊液雌二醇含量,进行重复性试验并与市场上现有的试剂盒进行比较,通过雌二醇含量的差异鉴定早期鸭胚性别。结果:雌性胚胎中雌二醇含量高于0.71 ng/mL,雄性胚胎中雌二醇含量低于0.59 ng/mL。研究表明,利用间接ELISA法可准确鉴定14日胚龄之后的胚胎性别,有益于动物福利和降低垂直疾病的传播。     

PCR扩增牙釉基因X和Y染色体不同序列鉴定牛早期胚胎性别

本实验利用牛牙釉基因特异性引物扩增牛血液、成纤维细胞和胚胎DNA,旨在优化牛早期胚胎性别鉴定的方法。结果表明:实验利用两温度PCR扩增母牛DNA样品获得1条来自X染色体458 bp产物,PCR扩增公牛DNA样品获得2条产物,其中395 bp扩增产物来自Y染色体,458 bp扩增产物来自X染色体,60头已知性别牛样品鉴定的准确率为100%。实验优化了一种两温度PCR快速鉴别奶牛及其早期胚胎性别的方法。     

鸽新城疫(ND)灭活疫苗安全性试验研究

用四批鸡胚尿囊液制备的ND油乳剂(Ⅰ号)灭活疫苗及鸡胚尿囊液、尿囊膜、羊膜、羊水混合制备的油乳剂(Ⅱ号)灭活疫苗和用鸡胚尿囊液制备的ND蜂胶佐剂(Ⅰ号)灭活疫苗及鸡胚尿囊液、尿囊膜、羊膜、羊水混合制备的蜂胶佐剂(Ⅱ号)灭活疫苗分别进行安全性试验观察,15d生长曲线表明,不影响鸽的生长,甚至有提高的趋势.     

快速检测IBV的平板凝集试验

美国学者 Miguel Ruano等建立了一种血凝 (HA)试验，用于快速检测鸡胚尿囊液中的传染性支气管炎病毒 (IBV)。试验检测了 468份疑似传支病鸡的气管和盲肠扁桃体样品。样品经处理后接种鸡胚尿囊腔，收集尿囊液，并用神经氨酸酶处理，然后取 50μ L酶处理的尿囊液与 5％的鸡红血球悬液 (CRBCs)在陶瓷板上混合，在 1 min内判定结果，凝集者为阳性。应用本方法检测接种一种或两种其它禽病病毒的鸡胚尿囊液，以测定其特异性。该方法的敏感性与鸡胚病变及 RT— PCR检测结果作比较。试验结果表明，这种平板血凝试验不仅敏感、特异，可重复性…     

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.     

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.     

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.     

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.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein     

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in     

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

Tropical Animal Health and Production -