猪链球菌活疫苗的研制

采用ST161菌种，经过肉汤培养后，加入适当保护剂，制成猪链球菌疫活疫苗。经过安全性、免疫效力等试验证明具有良好的免疫原性和保护力。     

鸡病毒性关节炎活疫苗对 SPF 鸡攻毒保护实验研究

本研究分别测定了两种病毒性关节炎活疫苗ZJS株和S1133株的TCID50。其中ZJS疫苗株的TCID50为104.5TCID50/羽份,S1133疫苗株的TCID50为103.5TCID50/羽份。通过进一步的攻毒保护实验,证实ZJS疫苗株对SPF鸡的临床保护力明显优于S1133疫苗株。     

复方中药对热应激肉鸡肝细胞保护作用研究

研究复方中药对热应激肉鸡肝细胞的保护效果。试验选18日龄AA+肉仔鸡120只,随机分为中药散剂组、中药颗粒剂组、中药超微粉组和热应激对照组,中药超微粉组按比例在饮水中添加自制中药超微粉,中药散剂组和颗粒剂组按比例添加相应药物,对照组不添加任何药物,试验期15 d。试验结束后每组迅速随机捕杀鸡3只,取肝脏组织进行组织切片和超微结构切片制作,并在显微镜下观察。结果显示,各试验组肉鸡肝细胞都得到不同程度保护,不同剂型保护程度有一定差异,其中中药颗粒剂组和中药超微粉组效果优于中药散剂组。说明该复方中药对热应激肉鸡肝细胞有一定的保护作用。     

肉鸡热应激及预防措施

近几年,随着肉鸡养殖的集约化、规模化发展以及全球性气温的普遍升高,肉鸡因热应激而导致的死亡越来越多,探索缓解热应激的有效措施,对促进肉鸡养殖业的健康发展,有着十分重要的意义。     

鸡球虫病四价活疫苗免疫保护效果试验

长期以来,本病的防治一直依赖药物,但是随着药物的广泛使用,球虫抗药性问题日趋普遍和严重,用于防治鸡球虫病的药物选用范围越来越窄,因此,免疫将成为预防球虫病的主流。为了进一步检验鸡球虫病四价活疫苗的免疫保护效果,同时观察该疫苗对鸡增重和饮食的影响,为其在生产中的推广应用提供依据,特进行以下试验。     

热应激对肉仔鸡热应激蛋白转录的影响

试验选270只28日龄AA肉用公鸡,随机分为3组,每组6个重复,每重复15只鸡,分别饲养于3个环境控制舱中.采用配对试验设计,各组温度分别为,持续日变高温组为28℃～34℃～28℃,适温自由采食组和适温配对组都为22℃.高温组和适温组鸡自由采食,配对组鸡喂给高温组前1 d的饲料采食量.于试验第2、5、8、12、15和22天每重复取1只鸡屠宰,测定旰中HSP72mRNA含量.试验结果表明:高温和限饲均导致肝中HSP72 mRNA含量升高,第22天高温组与适温组差异显著.试验说明,HSPs可作为热应激的一个敏感指标.     

猪瘟淋脾毒耐热保护剂活疫苗保存期的测定及免疫保护试验

对添加耐热保护剂的猪瘟淋脾毒活疫苗进行保存期的测定和保存后的免疫保护试验.结果表明,研制的猪瘟淋脾毒耐热保护剂活疫苗在2～8 ℃条件下保存24个月后免疫猪,能100%抵抗猪瘟石门系强毒的攻击.     

猪瘟活疫苗(传代细胞源)免疫猪的攻毒保护试验

为进一步证明猪瘟活疫苗(传代细胞源)在猪场实际使用的免疫效力,本试验将中试生产的5批疫苗在广东的广州、韶关地区各选一个猪场进行临床应用试验。按照20日龄首免,60日龄二免的免疫程序,并分别于二免后第28天和第90天从5批疫苗免疫猪中各抽取5头,连同条件相同的对照猪各5头,在广东永顺生物制药股份有限公司负压动物舍进行猪瘟强毒攻击,观察发病死亡情况,评估猪瘟活疫苗(传代细胞源)在猪场实际应用的免疫保护效果。试验结果显示,5批疫苗免疫猪均能有效抵抗猪瘟强毒的攻击,既无死亡,也无猪瘟临床症状。表明在临床条件下应用猪瘟活疫苗(传代细胞源)免疫猪能产生很好的免疫保护力。     

鸡热应激与热应激蛋白的作用机理研究

高温导致畜禽热应激问题的危害正日益突出并倍受关注。针对这些问题本刊推出“热应激专栏”,目的是为缓解夏季普遍存在的畜禽热应激提供理论和技术支持,使从业者能通过一些技术手段来规避热应激带来的损失。由于时间的仓促,本期组织的稿件内容覆盖面不是很全,但是以后会陆续推出有关内容,希望大家能继续关注。同时我们也希望专家、学者能踊跃地发表真知灼见与广大读者分享,把热应激理论、防制调控推到一个更高的阶段。     

一种疫苗稳定剂对含氯水中新城疫活疫苗(ND)的影响

将新城疫冻干活苗分别稀释在(a)蒸馏水,(b)含4 mL/L游离氯的蒸馏水,或(c)含有4 mL/L游离氯及疫苗稳定剂的蒸馏水中.分别在0和60 min测定蒸馏水组中SPF鸡胚的病毒效价,在30 min和60 min测定含氯水试验组及稳定剂试验组SPF鸡胚的病毒效价.测定结果表明,疫苗稳定剂可完全保护疫苗中病毒不受4 mL/L游离氯的有害影响.     

Characteristics of live bovine herpesvirus-1 vaccines

The common disease caused by bovine herpes virus 1 infection is febrile rhinotracheitis (FRT) and under certain conditions the virus is strongly implicated in pre-disposing cattle to pneumonic pasteurellosis. These illnesses account for a significant economic loss in the cattle industry worldwide and vaccination is widely applied. In naive cattle, and for a short period of time, old and new vaccines significantly reduce clinical signs of FRT and also virus shedding. A single intranasal vaccination affords significant protection in face of maternally derived antibodies, and the protection can be significantly prolonged by a booster intramuscular vaccination. Current data recommend vaccination in face of an outbreak and vaccines appear safe for pregnant cattle.     

Aromatic-dependent Salmonella typhimurium as modified live vaccines for calves

Strains of Salmonella sp with complete nonreverting aromatic biosynthesis (aro) defects are expected to be nonvirulent, in respect to invasive infection, because they need the aromatic metabolites paraaminobenzoate (for making folate) and dihydroxybenzoate (for making enterochelin) which are not available in host tissues. Derivatives with transposon-generated complete nonreverting aro-defects were prepared from 3 mouse-virulent strains of S typhimurium, namely, FIRN, WRAY, and UCD. The latter 2 parent strains originally were isolated from calves and are known to be calf-virulent. The resultant aromatic-dependent (aro-) strains were used to vaccinate 27 calves (2 to 3 weeks old), usually giving 2 doses by the IM route (10(9) bacteria) or orally (1.5 X 10(11)). Vaccination did not cause severe ill effects in any calf. Thus aro- defects cause loss of virulence for calves, as previously shown for mice. Vaccinated and control calves were challenge exposed, usually at 5 weeks of age, by feeding 1.5 X 10(11) cells of 1 of 2 calf-virulent S typhimurium strains, either UCD 108-11 or SL1323. Of the 16 challenge-exposed control calves, all became anorectic and depressed (CNS), and 15 had diarrhea. Fourteen of the 16 died; all tested tissues were bacteriologically culture-positive for Salmonella at necropsy. Vaccination with the live UCD aro- vaccine strain, SL1479 by either of 2 schedules (IM or orally) appeared effective.(ABSTRACT TRUNCATED AT 250 WORDS)     

Persistence of commercial modified live reovirus vaccines in chicks

Four modified live reovirus vaccines were compared with a field isolate (81-176) of reovirus for safety in 1-day-old and 1-wk-old specific-pathogen-free chicks. At 1, 3, 5, and 7 wks after vaccination, blood, cloacal swabs, and hock tendon samples were collected and assayed for residual virus. Tendon samples were also examined microscopically and scored for histological changes. Vaccine efficacy was monitored by challenging chicks 7 wks postvaccination via the footpad with the 81-176 isolate. Serum samples were collected throughout the trials and assayed for reovirus antibodies using an enzyme-linked immunosorbent assay. In chicks vaccinated at 1 day of age, three of the four vaccine viruses were consistently recovered from the hock tendon tissues. Post-challenge virus recoveries were similarly positive for the same vaccine viruses. Histological lesion scores of the tendons paralleled the degree of virus recovery. In the chicks vaccinated at 1 wk old, none of the vaccine viruses were recovered, nor were tendon lesion scores substantially elevated. Following challenge, however, virus was recovered from all vaccinated groups.     

IgM responses in chicken serum to live and inactivated infectious bronchitis virus vaccines.

Intramuscular (i.m.) administration of infectious bronchitis virus (IBV) oil-emulsion vaccine (OEV) to IBV-primed or unprimed chickens resulted in the production of zero or minimal concentrations of IBV-specific IgM in the serum, as measured by enzyme-linked immunosorbent assay of gel chromatography fractions. Live-attenuated infectious bronchitis (IB) vaccine given i.m. or by eyedrop stimulated the production of IBV-specific IgM in similar amounts following inoculation by both routes. These levels were comparable to those found in earlier studies following intranasal inoculation with a virulent strain of IBV and confirm that the detection of IBV-specific IgM is a valuable aid to the diagnosis of recent infection. As expected, administration of live-attenuated IB vaccines i.m. or by eyedrop protected the respiratory tract against challenge with virulent virus 24 days later; however, OEV given i.m. did not.     

Use and effectiveness of live vaccines in industrialized livestock production

There is an inseparable correlation between higher livestock performance and animal health with many visible repercussions in terms of further intensification of livestock farming. This is the background against which immunobiological action is defined as a major element of all efforts which are undertaken for the purpose of ensuring high-stability and high-continuity and no-problem production. Underlined in this paper is the great role played by legal provisions for immunisation concepts as well as by straight-forward guidance, organisation, and documentation of all uses of live vaccines. Practical experience so far obtained from the use of vaccines and its effects under conditions of industrialised livestock farming is reported in this paper, with particular reference being made to swine fever and transmissible gastro-enteritis of swine.     

Investigations on live vaccines against infectious bursal disease of chicks

Summary

Four live virus vaccines against Infectious Bursal Disease (IBD) were studied with regard to their safety, immune response and applicability. None of the vaccines caused clinical symptoms or had an adverse impact on bodyweight. Differences between these vaccins were observed in their effect on the Bursa/ Bodyweight Ratio and the severity of the microscopical lesions of the bursa Fabricii. The immunosuppressive effect of IBD vaccination at one day of age on the response to Newcastle disease vaccine applied was rather low.

Three of the four vaccines induced antibodies associated with protection against challenge. Vaccination of SPF rearing chickens by drinking water at an age of 15 weeks produced an antibody response (Agar Gel Precipitin Test) whereas at an age of 23, 32 and 60 weeks it did not. Chickens of all age groups responded serologically to an intramusculair vaccination.

A correlation was found between the immunological response and the effect of the vaccines on the bursa Fabricii.     

Immunizing against salmonella infections with live and inactivated vaccines]

A live attenuated auxotrophic S. typhimurium (S. tm.)-mutant was used by orally administration via drinking water several times during rearing, combined with 1- or 2-times parenteral injection of an autogenous S. enteritidis (S. e.)/S. tm.-oil emulsion vaccine. In a 8-month period, more than 500,000 birds were vaccinated. The vaccine was safe. Challenge test showed protection in the vaccinates and their offspring. The number of isolates in the farms detected by regular monitoring decreased. The protection of the live-culture mutant lasted about only 8 to 10 weeks. A. S. tm.-mutant more potent for chickens will be tested now. We consider vaccinations as one important factor in a salmonella control program, especially for commercial layers and broiler breeders.     

Investigations on live vaccines against infectious bursal disease of chicks

Summary Four live virus vaccines against Infectious Bursal Disease (IBD) were studied with regard to their safety, immune response and applicability. None of the vaccines caused clinical symptoms or had an adverse impact on bodyweight. Differences between these vaccins were observed in their effect on the Bursa/ Bodyweight Ratio and the severity of the microscopical lesions of the bursa Fabricii. The immunosuppressive effect of IBD vaccination at one day of age on the response to Newcastle disease vaccine applied was rather low. Three of the four vaccines induced antibodies associated with protection against challenge. Vaccination of SPF rearing chickens by drinking water at an age of 15 weeks produced an antibody response (Agar Gel Precipitin Test) whereas at an age of 23, 32 and 60 weeks it did not. Chickens of all age groups responded serologically to an intramusculair vaccination. A correlation was found between the immunological response and the effect of the vaccines on the bursa Fabricii.