腺胃型鸡传染性支气管炎病毒的初步分离与鉴定

为了获得更多的腺胃型鸡传染性支气管炎病毒分离株并研究其生物学特性,试验从黑龙江省某鸡场发生的以腺胃肿大为特征的病死鸡中分离到1株具有冠状病毒特性的病毒,通过鸡胚传代、血凝性测定、电镜观察、RT-PCR检测和动物回归试验对其进行了初步鉴定。结果表明:该病毒分离株在SPF鸡胚上传至第5代开始出现死亡或典型的侏儒胚;病毒不能直接凝集鸡红细胞,经1%胰酶处理后表现出血凝活性,血凝效价达28;透射电镜下可见有囊膜和纤突,直径为80～120nm的病毒粒子,具有冠状病毒的典型形态特点;分离株病毒第5代尿囊液经N基因特异性RT-PCR获得大小约438bp的目的片段;分离株病毒第5代尿囊液接种于14日龄SPF雏鸡,复制出与临床中相似的病理变化,同时从肿大的腺胃中能重新分离到该病毒。初步确定所分离病毒为腺胃型鸡传染性支气管炎病毒。     

腺胃病变型鸡传染性支气管炎病毒的分离鉴定及免疫试验

从山东省某鸡场发生的以腺胃肿大为特征病变的病鸡群中分离获得了 1株具有冠状病毒特性的病毒。该分离毒株在电镜下可见到直径为 80～ 14 0 nm、有囊膜及纤突呈冠状排列的病毒粒子。感染鸡胚的尿囊液没有血凝活性 ,经1%胰酶处理后能凝集鸡红细胞 ,其血凝活性可被传染性支气管炎部分毒株的阳性血清所抑制 ;经 SPF鸡胚传代时 ,可使胚胎发生规律性死亡 ,胚体卷缩 ,呈现明显的侏儒胚特征 ;接种于 10日龄 SPF雏鸡 ,从具有相似病变特征的病鸡腺胃组织中可再分离到该病毒。血清中和试验表明 ,部分传染性支气管炎病毒株阳性血清对其具有不同程度的中和作用。据此 ,确定该分离株为可导致鸡腺胃肿大的传染性支气管炎病毒。用具有腺胃肿大病变的病鸡脏器制备的组织灭活疫苗和用传代鸡胚尿囊液制备的油乳剂灭活疫苗 ,可使鸡获得较好的免疫力 ,能有效地预防本病的发生     

鸡传染性支气管炎病毒BJ0903株的分离鉴定

从北京某养鸡场疑似肾型传染性支气管炎病死鸡的肾脏和肺脏组织中分离到一株病毒,经SPF鸡胚连续传代、血凝试验、鸡胚矮小试验、干扰新城疫病毒复制试验、PCR鉴定和动物回归试验,初步确定该病毒为鸡传染性支气管炎病毒,命名为BJ0903株。     

鸡肾型传染性支气管炎病毒的分离鉴定

2012年3月,新郑市某蛋鸡场发生了1例疑似肾型传染性支气管炎病,取剖检病鸡的气管和肺脏组织经过无菌处理,分离到1株病毒。为确定该病毒,应用病毒分离、血凝试验、鸡胚矮小化试验、干扰新城疫病毒复制试验、琼脂凝胶扩散试验、RT-PCR鉴定和动物回归试验方法鉴定,结果均符合鸡肾型传染性支气管病毒的生理特性。通过检查结果结合临床、剖检症状,确认该病毒就是鸡肾传染性支气管炎病毒。     

一株鸡传染性支气管炎病毒的分离和鉴定

对枣庄市某养鸡场送检的疑似鸡传染性支气管炎病料进行分离和鉴定,通过发病鸡场病鸡临床症状观察,病理解剖,实验室PCR检测,鸡胚致病性试验、血凝实验,对鸡新城疫病毒的干扰试验、动物回归试验等,一系列试验结果表明,该病的临床症状和病理变化典型,实验室PCR检测为鸡传染性支气管炎阳性,病料处理接鸡胚后,24-48h鸡胚全部死亡,死亡鸡胚表现失水、蜷缩、发育小等特异性病痕,收获的鸡胚尿囊液无血凝性,分离毒对NDV感染有干扰作用;动物回归试验接种SPF雏鸡可复制出现鸡传染性支气管炎的典型症状。表明该鸡场确实发生了鸡传染性支气管炎病毒的感染,春季是该病的高发季节,应加强对该病的诊断和防控。     

鸡传染性支气管炎病毒的分离与鉴定

为对某鸡场发生的呼吸道疫病进行确诊,并对致病原进行分离和鉴定,本研究进行了发病鸡场临床诊断、病毒分离、分离毒株血凝试验、分离毒株RT-PCR检测以及序列分析等系列试验。试验结果显示,该病的临床特征疑似鸡传染性支气管炎病毒感染,临床病料样品接种鸡胚后可引起鸡胚死亡以及"侏儒胚"等典型症状,分离毒株无血凝性,分离毒株经传染性支气管炎病毒特异性引物检测为阳性,且序列分析显示RT-PCR扩增产物为鸡传染性支气管炎病毒特异性核苷酸序列,表明引起鸡场此次疫病的致病原为鸡传染性支气管炎病毒。     

鸡传染性支气管炎病毒山东分离株S1的测序分析及致病性

从山东某地疑似患肾型鸡传染性支气管炎(IB)的病死鸡的肝、肺、肾脏中分离到1株病毒,经过SPF鸡胚传代接种、血凝试验、鸡胚矮化试验、RT-PCR鉴定及测序分析、动物回归试验,确定为鸡传染性支气管炎病毒,并命名为SD/04/18株。结果显示,经3%胰蛋白酶处理后,病毒分离株有血凝性,未经处理病毒分离株不具有血凝性;鸡胚矮化试验发现该毒株明显抑制胚胎发育;进化树比对发现,该毒株与我国主要流行的QX株同源性最高,S1基因序列相似性为96.4%,氨基酸序列相似性为95.3%。分离株用SPF鸡胚连续传3代后接种8日龄SPF雏鸡,复制出了与自然病例相同的临床症状,肺、脾、肾、气管等器官出现典型病理变化。免疫组织化学法检测在气管环纤毛、肾小管上皮细胞间隙等部位可见抗原聚集。对被感染试验鸡的口腔、泄殖腔排毒进行跟踪检测,直到试验结束,被感染鸡仍有很高的病毒检出率。结果表明,最终确定该毒株为肾型鸡传染性支气管炎病毒。     

六株传染性支气管炎病毒的生物学特性鉴定及遗传进化分析

从华南地区疑似传染性支气管炎的病料中,分离到6株传染性支气管炎病毒并对这些分离株进行鸡胚矮小化试验、新城疫病毒干扰试验、血凝特性试验、鸡胚气管环感染试验、S1基因的克隆测序与序列分析。结果表明,各分离株均对鸡胚有明显的致矮小化作用;对新城疫病毒有明显的干扰作用;无直接血凝性,经10g/L胰酶处理后,可凝集鸡的红细胞;对鸡胚气管环有明显的感染致病变作用;利用RT-PCR方法,成功扩增出分离株的S1基因,与参考株S1基因序列比对,其中1株(GD-09II)属于Mass型,剩下5株与LX4型亲缘关系较近。     

一株鸡肾型传染性支气管炎病毒的分离与鉴定

从山东某鸡场疑似肾型传染性支气管炎病死鸡的肾脏中分离到一株病毒,经SPF鸡胚连续传代、血凝试验、鸡新城疫干扰试验、鸡胚矮小化试验、RT—PCR鉴定和动物回归试验,初步确定该病毒为肾型传染性支气管炎病毒,并命名为SD1105株。     

一株肾型鸡传染性支气管炎病毒的初步分离鉴定

从哈尔滨市某肉鸡养殖场疑似传染性支气管炎的病死鸡中分离到1株肾型IBV,并对其进行鸡胚矮小化、血凝性、电镜下特征、新城疫干扰试验、致病性等生物学鉴定和N基因的RT-PCR鉴定。结果表明,该病毒分离株在鸡胚上传至第四代(F)4开始出现死亡或侏儒胚;病毒不凝集鸡红细胞;透射电镜下可见多呈球形、直径约80～120nm的病毒粒子,具有冠状病毒的典型形态特点;该病毒可干扰新城疫LaSota株在鸡胚中的增殖;将分离毒第4代尿囊液接种于6日龄雏鸡,7d后开始出现死亡,死亡率高达67%(6/9),病死鸡剖解后可见肾脏明显肿大、苍白,具有传染性支气管炎的典型病变;分离毒第5代尿囊液经N基因特异性RT-PCR获得大小约438bp的目的片断。初步确定所分离病毒为肾型IBV。     

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 -