鸡新城疫耐热保护剂活疫苗中试生产及区域试验

在鸡新鸡城疫耐热保护剂活疫苗的中试生产试验中 ,共生产疫苗 6批 ,计 775 0万羽 ,检验全部合格 ,在 2～ 8℃保存期达 2 4个月 ;在北京、河北、辽宁、天津选择了 5个鸡场进行区域试验 ,共免疫鸡 8 7万羽 ,免疫后 10～ 15d的HI抗体效价几何平均滴度 (GMT)达 1∶12 8～ 1∶2 5 6 ,对免疫鸡群进行追踪观察 ,未发生鸡新城疫疾病 ,证明此疫苗安全有效。     

鸡马立克氏病火鸡疱疹病毒(耐热保护剂)活疫苗的中试生产及区域试验

按照拟定的<鸡马立克氏病HVT(耐热保护剂)活疫苗制造及检验规程>(草案)在辽宁益康生物制品厂进行了5批该疫苗的中试生产,计3542万羽,检验全部合格;耐老化试验及保存期测定结果表明:该产品在2～8℃可保存24个月.在北京、河北、辽宁、广西、广东等地选择几个大型孵化厂进行区域试验,共免疫鸡700万羽,均未出现任何不良反应,跟踪观察,免疫鸡也未发生马立克氏病,表明该疫苗安全有效.     

土蛋鸡非典型新城疫的诊治

我市赵家镇某养鸡户，于2005年6月26日从萧山区购得土蛋鸡苗1500羽，当时按免疫程序要求进行免疫，7日龄新城疫L系疫苗1倍量滴鼻免疫，10日龄法氏囊2倍量饮水免疫，27日龄新城疫L系疫苗2倍量饮水免疫，60日龄鸡Ⅰ系疫苗1倍量肌肉注射，180日龄时用鸡减蛋综合征、传染性支气管炎、新城疫三联油苗免疫，每羽0．5ml肌肉注射。至2006年4月份，鸡群开始出现呼吸困难、下痢为主的症状．而且产蛋率下降，死亡7～8羽／d，最多一天死亡13羽，15d共死亡近150羽，死亡率达10％之余。     

鸡传染性支气管炎耐热活疫苗的研究

应用鸡传染性支气管炎病毒(H52株)与不同耐热保护剂配方和冻干曲线进行筛选.结果表明:采用冻干曲线2和耐热保护剂WXS冻干鸡传染性支气管炎病毒H52弱毒疫苗效果最佳.试制耐热活疫苗3批,其各项检验均符合要求.耐老化试验表明:经过37℃放置10d的每羽份病毒含量下降0.6～0.8个滴度,每羽份病毒含量达104.7～105.1EID50.保存期试验表明:2～8℃保存24个月疫苗每羽份病毒含量下降0.4～0.6个滴度,每羽份病毒达104.1～104.3EID50.疫苗2～8 ℃保存24个月后效检抗体水平达到1:16～1:32.免疫持续期试验表明:免疫21日龄SPF鸡,6个月后血清中和抗体效价达到1:32～1:64.田间试验表明临床观察无不良反应,安全有效.特异性试验表明耐热活疫苗抗原性不变.耐热保护剂生物学和理化特性表明保护剂安全、稳定,室温保存期达3个月.     

水貂病毒性肠炎杆状病毒载体灭活疫苗与水貂犬瘟热活疫苗混合免疫效果评价

为评价水貂病毒性肠炎杆状病毒载体灭活疫苗(简称MEV亚单位疫苗)与水貂犬瘟热活疫苗(简称CDV活疫苗)混合免疫的效果,本研究将两种疫苗混合后在室温静置不同时间测定犬瘟热病毒(CDV)含量,并选用30只健康水貂随机分为6组进行比对试验,其中G1和G2组免疫MEV亚单位疫苗稀释CDV活疫苗的混合疫苗,G3组为CDV活疫苗单独免疫组,G4组为MEV亚单位疫苗单独免疫组,G5和G6组分别为CDV攻毒组和MEV攻毒组。免疫后21 d采血检测CDV中和抗体,同时对G1、G3、G5组进行CDV攻毒;免疫后14 d采血检测MEV血凝抑制(HI)抗体,同时对G2、G4、G6组进行MEV攻毒。结果：两种疫苗混合后在室温静置2 h, CDV含量无明显下降。免疫后21 d, G1和G3组CDV中和抗体效价达到1∶64.6～1∶128.8,CDV攻毒后混合疫苗和CDV活疫苗免疫组的保护率均为100%。免疫后14 d, G2和G4组的MEV HI抗体效价达到1∶128～1∶1 024,MEV攻毒后混合疫苗和MEV亚单位疫苗免疫组的保护率均为100%。研究表明,MEV亚单位疫苗稀释CDV活疫苗,混合免疫后各疫苗的免...     

行业动态

山西禽流感疫苗全部到位免疫率保证100%本刊讯(特约记者刘平国):12月7日,1110万羽份禽流感疫苗紧急下发山西各市,这是为满足山西省家禽100%免疫率调拨的最后一批疫苗。按照防控高致病性禽流感的需要,山西省共需疫苗6580万羽份,经省防控高致病性禽流感指挥部的努力,派专人驻北京调拨疫苗。省农业厅副厅长董希德亲自到农业部汇报工作争取疫苗;防治站站长张树方带病3次到北京协调疫苗调拨事宜。从11月23日起陆续调回6628万羽份,比需要量超出48万羽份。本批疫苗的到位,为实现存栏家禽100%免疫率提供了重要的物质保证。江西家禽企业今年免征所得…     

鸡新城疫疫苗对鹅副粘病毒病免疫效果观察

本研究利用几种常规鸡新城疫（ND）疫苗进行了鹅副粘病毒病的免疫效果试验。240只20日龄ND抗体检测阴性的小鹅分为8组,每组30只。第1～3组鹅用2～5羽份（相对于鸡,下同）Ⅳ系苗首免,2周后用2或5羽份NDI系疫苗二免;第5和6组鹅用2羽份禽流感．鸡新城疫（AI-ND）二联活疫苗（rL-H5株）首免,3周后再用2或5羽份同种疫苗二免;第4和7组鹅分别用2羽份灭活油乳剂苗和2羽份Ⅳ系疫苗单免;第8组鹅为非免疫对照组。定期采血检测各组NDHI抗体水平,分别于单免或二免后第21d和140d每组抽5只鹅用鹅源副粘病毒强毒株JG97进行攻毒试验,攻毒剂量为400LD50/只。试验结果表明,第1～3组鹅免疫后产生的抗体水平较高,免疫保护期也较长。到二免后140d,这三组鹅的平均HI抗体水平仍维持在4log2矿左右,而且可完全抵抗强毒攻击。根据实验结果,建议生产上采用2羽份NDIV系苗首免、2周～3周后以2～5羽份NDI系苗二免的免疫程序预防鹅副粘病毒病。     

含兔出血症病毒VP60蛋白病毒样颗粒的兔三联灭活疫苗的研究

为研究兔出血症病毒(RHDV)VP60蛋白形成的病毒样颗粒联合多杀性巴氏杆菌(Pm)、产气荚膜梭菌(Cp)的免疫效果,将3种抗原与铝胶佐剂混合制成三联灭活疫苗,进行安全检验、最小免疫剂量测定及免疫持续期研究。结果表明,3批疫苗以4.0 mL/只免疫兔未见任何不良反应;对兔的最小免疫剂量为1.0 mL/只,免疫后14日,血清RHDV HI效价为1∶16～1∶64,攻毒后免疫兔均健活(5/5);免疫后21 d,用Pm和Cp分别攻毒,免疫兔80%以上(4/5～5/5)保护;免疫持续期可达210 d。RHDV VP60蛋白形成的病毒样颗粒可与Pm、Cp联合制备疫苗,解决了传统RHDV组织灭活苗生产过程存在的生物安全风险问题,同时实现了一针三防。     

蛋鸡生产中球虫免疫的应用效果与体会

慈溪市范市镇自1982年开始发展蛋鸡,至今已达20余万羽,育雏、育成、产蛋阶段都受到过球虫病的侵害.为预防球虫病的侵害,接种球虫疫苗是最理想的选择. 1 疫苗使用方法 选用美国Coccivac-D球虫活苗,每瓶1000头份,3～4日龄时饮水免疫.据多次实践,免疫剂量按70%算,即用7瓶疫苗免疫10000羽鸡.每羽雏鸡疫苗用水量约2.5～3.0ml.通常每1000羽雏鸡需放小饮水器20只以上,水量要求鸡只在1～2h内饮完,然后给予正常饮水.     

中药免疫增强剂对鸡ILT疫苗免疫和强毒攻击的影响

选择健康仔鸡 70只 ,随机分为 7组 ,每组 10只。 1组为健康对照组 (不免疫、不攻毒 ) ,2～ 4组为不同处理的免疫试验组。在试验仔鸡 45日龄时 ,2组免疫传染性喉气管炎 (ILT)疫苗 ,3组免疫ILT疫苗同时肌肉注射中药免疫增强剂Ⅰ ,4组免疫ILT疫苗同时肌肉注射中药免疫增强剂Ⅱ。 5、6组为非免疫试验组。在仔鸡 5 2日龄时 ,5组肌肉注射中药免疫增强Ⅰ ,6组肌肉注射中药免疫增强Ⅱ。 7组为单纯强毒攻击组。 5 5日龄时 ,2～ 7组全部用ILT强毒 (EID50 =10 -5 33/ 0 1ml)攻击。结果显示 :试验 2组在免疫后 3d ,RBC -CRl和RBC -IC花环率显著降低 ,免疫后第 9d ,上述两个花环率恢复到正常值。试验 3、4组 ,RBC -CRl和RBC -IC花环率在免疫后升高 ,且高于 1组和 2组。强毒攻击后 5d、10d ,试验 2～ 6组 ,RBC -CRl、RBC -IC花环率仍然保持在攻毒前的水平。 7组的RBC -CRl和RBC -IC花环率显著降低 ,与其他各组比较差异极显著 (P <0 0 1) ,在攻毒后第 10d(试验 2、3、4组免疫后 2 0d) ,体内ILT抗体检测结果为 ,试验 1组ILT抗体全部阴性 ,其他试验组的ILT抗体效价为 :2组、3组、7组为 1∶8;4组、5组为 1∶32 ;6组为 1∶2 5 6。说明ILT疫苗免疫或强毒攻击 ,均会引起机体红细胞免疫功能降低 ;中药免疫增强剂能够消除ILT     

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.     

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 -