鸡大肠杆菌多价灭活油乳疫苗的研制与应用

选择从山东不同地区分离的6个具有优势血清型的大肠杆菌菌株，经培养、混合、灭活后，用白油、吐温、司本，按一定比例混合，制备鸡大肠杆菌多价灭活油乳疫苗，安全性检验、效力检验、稳定性试验结果表明，该疫苗安全有效，接种后无不良反应，保护率达95%以上，4-8℃保存1年，20-25℃保存半年不失效。田间免疫试验和扩大区域试验结果表明，该疫苗性能良好、安全，对蛋鸡、肉鸡、雏鸡的生产性能无明显不良影响，经免疫后，因大肠杆菌的死亡率由对照组的7.5%、9.8%、4.6%降至2.1%、2.8%、1.8%。     

鸡产蛋减少综合症(EDS-76)油乳剂灭活苗的安全性及免疫效果观察

对鸡产蛋减少综合症油乳剂灭活苗进行了一系列安全性及免疫效果的观察.结果表明,疫苗对健康鸡很安全,每只鸡肌肉注射0.5 mL疫苗后,9 d产生免疫保护力,疫苗免疫期在12个月以上.疫苗4～8℃保存12个月以上,11～20℃保存3个月仍有免疫效果.此疫苗在甘肃省推广试用80万只份,安全可靠,免疫持续期长,能有效地预防和控制EDS-76的发生和流行.     

鸡新城疫病毒B_(95)株免疫研究

本试验采用鸡胚增殖培养鸡新城疫B95 株病毒。经对培养的尿囊液病毒价达EID50 107.75。无菌性检验和安全性检验均符合疫苗要求 ,将其选作试验用疫苗进行了试验。结果表明 ,该苗滴鼻点眼免疫的最小剂量为105.75,拌料免疫最小剂量为106.75。以B95 株疫苗滴鼻点眼免疫的鸡 ,在免疫后5天时就可产生坚强的免疫力 ,免疫期可达4个月。同居接触免疫鸡能获得了良好的免疫效果 ,攻毒总保护率与滴鼻点眼免疫差异不显著。拌料免疫效果良好 ,与NDV滴鼻点眼免疫差异不显著。B95 株苗在0～4℃条件下保存4个月 ,免疫攻毒保护率达80% ;在室温下保存2个月 ,免疫攻毒保护率达100%。     

禽巴氏杆菌、大肠杆菌、沙门氏菌三联油乳灭活苗的研制及试用

以多杀性巴氏杆菌 (C-481 )、致病性大肠杆菌 O85、O119、O18、鸡白痢沙门氏菌等菌株制备的禽巴氏杆菌 大肠杆菌 鸡白痢沙门氏菌的油乳与中药灭活菌苗 ,经实验室免疫试验和中间试验证明 ,该菌苗在免疫后第 1 4天即可产生坚强的免疫力。经攻毒试验证明 ,该菌苗的保护率为 93 % ,免疫期为 9个月 ,免疫效果普遍反应良好。该菌苗在 4℃可保存 1 8个月以上 ,室温阴暗处可保存 1 0个月以上。临床证明该菌苗能有效地控制禽巴氏杆菌病、大肠杆菌病与鸡白痢在鸡群中的流行 ,可进行推广应用。     

鸡大肠杆菌病中草药佐剂多价灭活苗的研制Ⅱ.疫苗免疫产生期、免疫持续期及保存期试验

对鸡大肠杆菌中草药佐剂多价灭活苗进行了免疫产生期、免疫持续期、疫苗保存期试验。研究表明 :雏鸡接种该疫苗 3～ 5d后便产生免疫力 ,到 9d时抗体产生水平已经很高 ;以免疫攻毒保护率不低于 80 %为标准 ,疫苗的免疫持续期可在 7个月以上 ;以物理性状合格和免疫攻毒保护率不低于 80 %为标准 ,疫苗置 4℃时保存期为 18个月 ,2 5℃保存 6个月为宜。     

鸭疫里默氏杆菌（10型）灭活疫苗的研制

以10型鸭疫里默氏杆菌GN52株为菌种,采用改进的液体培养工艺进行增菌后,制备油乳剂灭活疫苗,经无菌和安全检验合格后,进行免疫原性研究。结果表明,对3日龄雏鸭颈部皮下注射0.3 ml/羽即可产生良好的免疫应答,免疫后7 d用同源菌株攻击保护率可达70%,14 d达100%,至56 d免疫保护率仍可达80%。于10日龄进行第2次免疫,二免后3 d免疫保护率达100%。疫苗免疫雏鸭后能够显著（P〈0.05）或极显著（P〈0.01）地增强其T细胞的免疫力,时间达2周。疫苗在4-8℃可保存1年,保存6个月和1年的保护率分别达95%和85%。该疫苗经田间试验,效果良好。     

鸡传染性鼻炎二价油乳剂灭活疫苗的保存期检验

应用3批鸡传染性鼻炎二价油乳剂灭活疫苗进行了保存期检验,结果表明,二价苗在4～8℃保存12个月和18个月后免疫鸡群,鸡群对A、C型强致病力菌株的保护率在二免后4周左右分别为100%和88.5%,血清SPA、阻断ELISA和HI抗体阳性检出率较高,但疫苗保存18个月后所免疫鸡的血清C型HI抗体效价的几何平均数有显著的下降.因此,该二价苗的保存期以12个月为宜.     

鸡新城疫法氏囊病联苗中新城疫的安全性及免疫效果的观察

研制了鸡新城疫法氏囊病油乳灭活苗,灭活苗免疫鸡无任何不良反应,用血凝抑制(HI)试验测定循环抗体水平及强毒攻击试验,结果表明,免疫力可维持6个月以上,对鸡新城疫的保护力达96%,疫苗在40℃保存6个月,实验室免疫力仍为100%.     

鸡新城疫/传染性支气管炎二联油乳剂灭活疫苗试验研究报告(Ⅲ)——二联苗安全性、免疫效力及保存期试验

用同胚培养的含NDV、IBV胚液制备的二联油乳剂灭活苗(简称鸡二联灭活苗),经免疫效力试验表明,用50倍稀释的鸡二联灭活苗,0.5ml/只剂量免疫18日龄鸡,4周后试验免疫鸡分别进行NDV、IBV强毒攻击,攻毒保护率均在50%以上,证明0.5ml剂量含有50个半数保护量(50个PD_(50)),NDHI抗体≥1:16,IBVN抗体≥1:8便可保护.三批疫苗免疫18日龄鸡,0.5ml/只组免疫鸡体内有效抗体可维持16周以上,0.25ml/只组有效抗体可维持到12周.疫苗在20℃保存4个月有效,4~8℃普通冰箱中保存15个月有效.以3倍免疫量免疫18日龄鸡4周内无任何毒副反应.     

鸡传染性法氏囊病BJ836弱毒株培育的研究

BJ836—IBD弱毒株是复制西德TAD鸡胚制品疫苗,将其培育为由鸡胚成纤维细胞制备的毒株。经测定,BJ836毒株在鸡胚成纤维细胞上连续传递5代毒价稳定在10~(7.0)TCID_(50)/0.1ml;经-10℃保存6个月,4℃保存1个月,北京夏季室温保存5天其毒价变化微小。用敏感雏鸡连续传递5代观察,此毒株对鸡法氏囊无明显的损害,接种无IBD抗体的鸡胚可致鸡胚死亡,具有一定的致病力。此毒株免疫雏鸡15天后,测定免疫中和抗体效价最高可达1∶3236,保护率达100%;免疫30天后最高可达1∶6456,保护率100%;对鸡新城疫疫苗无免疫抑制作用。由于此毒株可以用IBD母源抗体阳性鸡胚制备的成纤维细胞繁殖,因此解决了必须用无IBD母源抗体的种蛋制备疫苗的困难。     

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.     

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     

Evaluation of the Microbiological Status of Milk and Various Structures in Mammary Glands from Naturally Infected Dairy Cows

A knowledge of the microbiological status of milk and of the different structures in the mammary glands has great importance in elucidating the pathogenesis of mammary gland infections. The objective of this study was to evaluate the microbiological status of various structures in the mammary glands from naturally infected dairy cows following slaughter. A total of 94 samples of milk, 184 samples of mammary parenchyma, 168 samples of gland cisterns, and 168 samples of teat cisterns were collected for microbiological examination. Microorganisms were detected in 59.9% of all samples, 67.0% of the milk samples, 70.1% of the mammary parenchymas, 55.9% of the gland cisterns and 48.8% of the teat cistern samples. When all samples were considered, coagulase-negative Staphylococcus were the most prevalent (35.7%) followed by coagulase-positive Staphylococcus (12.2%), Corynebacterium bovis (2.4%), Prototheca sp. (1.9%), and Streptococcus dysgalactiae (1.5%). There was a significantly higher occurrence of microorganisms in the milk and mammary parenchyma compared to the gland cisterns and teat cisterns. This revised version was published online in July 2006 with corrections to the Cover Date.     

Development and survival of free-living stages of gastrointestinal nematodes of sheep and goats on pasture in the Nigerian derived savanna

Four grass plots were sequentially contaminated with goat faeces containing known numbers of unembryonated eggs of predominantly Haemonchus contortus and Trichostrongylus spp. between October 1982 and April 1983. Four other plots were similarly contaminated with sheep faeces between February and May 1987. An additional plot was repeatedly contaminated with sheep faeces from February to April 1987. Populations of free-living stages in faeces and of infective larvae (L₃) in the herbage were subsequently monitored until the end of April and June of 1983 and 1987 respectively. During February and May 1987 two control cultures of sheep faeces were incubated in the laboratory at 25°C–30°C and at a constant temperature of 50°C and the free-living development was also monitored. L₃ developed very readily in the faeces cultured at 25°C–30°C and in those spread on a grass plot in October, at the end of the wet season, but developed less on the plot contaminated in May at the start of the wet season. Worm eggs in faeces deposited on plots during the hot dry season (December to April) or incubated at 50°C died and disintegrated after 24–48 h exposure to the high environmental temperatures. The results indicate that it is unlikely that gastrointestinal nematodes of sheep and goats can develop or survive on open pasture during the dry season in the Nigerian derived savanna zone.