强效艾美耳牌鸡球虫苗的免疫效果

在实验条件下,研究了强效艾美耳牌鸡球虫苗对平养鸡群的免疫效果。实验１比较了免疫鸡群和对照鸡群在接种后１、２、３、４、５、６周的肠道病变分,结果表明免疫鸡群较自然感染建立免疫的对照鸡群的免疫整齐度高,判断依据是免疫后２周盲肠细小、内容物亦少的眼观指标。实验２比较了免疫鸡群、不免疫不用药鸡群、不免疫用药鸡群在攻虫后的三处肠道病变,结果表明免疫鸡群对大剂量卵囊攻击有很强的抵抗力。实验３比较了免疫鸡群、不     

影响新城疫免疫效果的因素及防疫对策

鸡新城疫分布广、传播快、危害大,是我国法定一类动物疫病,需实施强制免疫。但在部分城乡养殖鸡群实施免疫后,发现部分鸡群免疫效果不一,出现了鸡群免疫有时效果好,有时免疫效果差,一些鸡群免疫效果好,另一些鸡群免疫效果差,导致近几年鸡     

蒙东地区蛋鸡新城疫免疫效果监测及分析

对蒙东地区25家蛋鸡养殖场12 400羽蛋鸡的新城疫免疫情况及免疫效果进行跟踪监测及对比分析,结果所有蛋鸡群的新城疫抗体效价和免疫合格率均符合农业部规定标准;产蛋前采用新城疫Ⅰ系+灭活苗免疫的鸡群抗体效价及生产性能要优于用Ⅳ系+灭活苗免疫的鸡群;产蛋期不免疫新城疫的鸡群,其抗体效价、免疫合格率和生产性能均较高;产蛋期免疫越频繁,蛋鸡的抗体水平和生产性能越低。表明鸡群产蛋前采用新城疫Ⅰ系+灭活苗的方式免疫效果较好;产蛋期间不宜频繁免疫新城疫疫苗;新城疫抗体水平的高低与鸡群的健康状况及安全生产指数存在正相关。     

鸡群疫苗免疫失败的原因及预防措施

按照正确的方式接种疫苗,是预防鸡群传染病经济、方便和有效的措施。影响疫苗免疫效果的原因众多,鸡群免疫失败的情况时有发生。笔者分析了鸡群免疫失败的原因,并提出了相应的预防措施,以期为养殖场(户)有效地进行鸡群免疫提供参考。     

鸡群免疫失败的原因与预防

<正>免疫接种是预防鸡群传染病的有效方法之一,免疫接种能否获得成功,不但取决于接种时疫苗的质量、接种操作流程和免疫程序等外部条件,还取决于鸡群的健康状况、机体的免疫应答能力等内部因素,所以接种过疫苗的鸡群不一定都能产生坚强的免疫力。近年来,一些免疫鸡群常常爆发传染病,给养鸡生产造成较大的损失。笔者根据近几年的生产实践和调查分析,就引起鸡群免疫失败的因素及防制对策介绍如下。1鸡群免疫失败的原因     

鸡群抗体监测的重要性

疫苗免疫接种是控制鸡病流行的主要途径之一,鸡群的免疫保护以体液免疫(包括循环抗体和局部粘膜抗体)和细胞免疫为主.而细胞免疫、局部粘膜免疫抗体均不易用实验室方法评价,只有循环抗体即血凝抑制抗体可以用常规的血凝与血凝抑制方法检测,并且循环抗体可以代表鸡群的整体免疫状况.但鸡群免疫抗体的产生及维持时间受到鸡群免疫应答能力、所用疫苗种类、免疫方法、免疫次数、疫病流行状况等方面的影响,良好的免疫接种不等于鸡群能够产生良好的保护力.     

禽流感H9非免疫鸡场与免疫鸡场鸡群HI抗体的比较研究

为了解禽流感H9在非免疫鸡群的感染情况和免疫鸡场的免疫效果,本试验在四川分别选择一个非免疫鸡场和免疫鸡场,用微量HI试验对187份不同日龄的非免疫鸡血清(56、85、92、149、256、410日龄)和222份不同日龄的免疫鸡血清(53、87、145、264、398日龄)进行了抗体检测,结果显示:非免疫鸡群禽流感H9阳性率分别为34.38%、37.14%、29.41%、38.71%、46.67%、52.00%,免疫鸡群阳性率分别为76.27%、84.31%、88.37%、91.89%、81.25%。试验表明非免疫鸡群的禽流感H9感染较严重,免疫鸡群免疫后的效果较好。     

防止鸡群免疫失败的三大技术措施

免疫是预防和控制鸡传染病的重要手段,几乎所有鸡群都需采取免疫接种.然而在实际生产中鸡群免疫接种后.仍不能抵抗相应疾病的流行,旧病复发,新病迭出,造成免疫失败.要想避免鸡群免疫失败.就必须针对引起鸡群免疫失败的原冈,只有考虑到每一个影响环节,做好每一个细节工作,才能真正保证鸡群免疫接种的效果,避免因免疫失败而造成的经济损失.具体而言,就是要做好制定科学的免疫程序、执行正确的免疫方法和加强综合性防治措施三个方面的技术措施.     

影响鸡新城疫免疫效果的因素及对策

鸡新城疫(ND)分布广、传播快、危害大，是国家法定一类动物疫病，实施强制免疫。我们在对城乡养殖鸡群实施ND免疫后，发现部分鸡群免疫效果不一、不稳定。出现了鸡群有时免疫效果好，有时免疫效果差；一些鸡群的免疫效果好，另一些鸡群的免疫效果差，有的甚至无效等现象。     

提高鸡群免疫效果措施和策略

近些年来,鸡群养殖过程中容易出现较多种类的疾病,时常发生隐性感染、混合感染等现象,严重影响到鸡群的健康生长。鸡群免疫在鸡疫病预防、控制方面发挥着十分关键的作用,但受疫苗质量、操作规范性等因素的影响,经常出现鸡群免疫失败问题,导致接种免疫的价值得不到体现。针对这种情况,养殖人员要规范、科学开展鸡群免疫工作,提高鸡群免疫效果,降低各类鸡疫病的发生几率。     

Turnover of Village Chickens Undermines Vaccine Coverage to Control HPAI H5N1

Highly pathogenic avian influenza (HPAI) subtype H5N1 remains an enzootic disease of village chickens in Indonesia, posing ongoing risk at the animal–human interface. Previous modelling showed that the fast natural turnover of chicken populations might undermine herd immunity after vaccination, although actual details of how this effect applies to Indonesia's village chicken population have not been determined. We explored the turnover effect in Indonesia's scavenging and mixed populations of village chickens using an extended Leslie matrix model parameterized with data collected from village chicken flocks in Java region, Indonesia. Population dynamics were simulated for 208 weeks; the turnover effect was simulated for 16 weeks after vaccination in two ‘best case’ scenarios, where the whole population (scenario 1), or birds aged over 14 days (scenario 2), were vaccinated. We found that the scavenging and mixed populations have different productive traits. When steady‐state dynamics are reached, both populations are dominated by females (54.5%), and ‘growers’ and ‘chicks’ represent the most abundant age stages with 39% and 38% in the scavenging, and 60% and 25% in the mixed population, respectively. Simulations showed that the population turnover might reduce the herd immunity below the critical threshold that prevents the re‐emergence of HPAI H5N1 4–8 weeks (scavenging) and 6–9 weeks (mixed population) after vaccination in scenario 1, and 2–6 weeks (scavenging) and 4–7 weeks (mixed population) after vaccination in scenario 2. In conclusion, we found that Indonesia's village chicken population does not have a unique underlying population dynamic and therefore, different turnover effects on herd immunity may be expected after vaccination; nonetheless, our simulations carried out in best case scenarios highlight the limitations of current vaccine technologies to control HPAI H5N1. This suggests that the improvements and complementary strategies are necessary and must be explored.     

Copper toxicosis in cattle fed chicken litter

Cattle from 2 herds developed copper toxicosis after the ingestion of chicken litter. The affected animals were adult Holstein cows and crossbred steers that ate 9 to 16 kg of litter/day. These cattle developed a sudden onset of weakness, depression, anorexia, icteric mucous membranes, and dark reddish brown urine. Liver copper concentrations in 2 cattle (1 from each herd) were 436 and 730 ppm. Results of copper analyses of chicken litter ranged from 620 to 920 ppm. Sodium molybdate and sodium thiosulfate were added to the ration of the dairy herd. Two cows with clinical signs of copper toxicosis recovered after being given additional sodium molybdate and thiosulfate supplements, orally.     

IgM rheumatoid factor in cattle immunized against babesiosis.

Polyclonal bovine IgM-rheumatoid factors (IgM-RFs) were examined in sera of cattle immunized against babesiosis. An enzyme-linked immunosorbent assay (ELISA) was used enabling rapid screening of serum samples. Results obtained indicate a rise of serum IgM-RF levels with age in healthy bovines. However when animals of similar age and pertaining to the same herd were examined, levels of serum IgM-RF exhibited a wide distribution range. Mean values in 60 sera of 2 yrs old clinically healthy heifers originating from a single herd were of 452.60 +/- 201.26 e.u. at 1 in 1,000 serum dilution and of 202.37 +/- 137.86 e.u. at 1 in 4,000 serum dilution. In a herd where repeated vaccination of dams against babesiosis was carried out 3 to 6 weeks before delivery either with live Babesia bovis parasites or soluble antigens of in vitro grown organisms, no significant differences in mean IgM-RF values were found between revaccinated animals and a control group. Nor did the mean values of serum IgM-RF of calves born to the respective groups of dams exhibit significant differences. It thus appears that immunization of healthy cattle against this parasite does not affect mean serum IgM-RF levels.     

陕西某种鸡场大肠埃希菌血清型调查与灭活苗研制

为控制大肠埃希菌病的危害,对从陕西某种鸡场分离鉴定的20株鸡大肠埃希菌进行了血清型调查,结果O2型5株、O6型3株、O78型4株,未定型8株,表明鸡场的大肠埃希菌有了新的流行菌株O6出现。用定型的分离菌株研制的自家灭活菌苗免疫接种雏鸡,7 d后可检测到抗体,14 d产生免疫保护力。29日龄二免,90 d后抗体水平仍在5log2以上。119日龄三免,免疫后5个月抗体水平仍维持较高,但6个月后,抗体水平已在5 log2以下,失去保护力。通过3年的应用,该场种鸡大肠埃希菌病的平均死亡率由6.7%下降至1.6%,雏鸡死亡率由4.2%下降至1.8%,差异极显著(P<0.01)。     

Corynebacterium pseudotuberculosis infection in goats. IX. The effect of vaccination against natural infection

A vaccination trial was carried out in 10 infected herds. The trial included 247 female kids, the number of animals in each herd varying from 15 to 38. About half of the animals in each herd were vaccinated twice at 3 to 4 week intervals, the first vaccination being carried out before the age of 4 months. A combination of a crude filtrate of C. pseudotuberculosis toxoid with whole organisms, was used. Overall, the prevalence of animals with superficial swellings was higher in the unvaccinated than in the vaccinated group during the first 1-2 years following immunization. However, in some herds superficial swellings were as common in vaccinated as in unvaccinated animals. An antibody response following vaccination was demonstrated in the hemolysis inhibition test, but not in the bacterial agglutination test. Superficial swellings were more common in vaccinated animals which were negative than in animals which were positive in the hemolysis inhibition test at 1 1/2 months after vaccination. The vaccine used in the present study, was not sufficiently efficacious to be recommended as the only protective measure against caseous lymphadenitis in Norwegian goat herds.     

Serological characterization of Haemophilus pleuropneumoniae (Actinobacillus pleuropneumoniae) strains and proposal of a new serotype: serotype 9

Ten strains of H. pleuropneumoniae isolated from 10 herd outbreaks of pleuropneumonia were studied by means of the slide agglutination test, the indirect haemaggluitiniation (IHA) test and by gel diffusion. The strains were antigenically homogeneous and serologically distinct from serotypes 1 through 8. It is therefore proposed to refer these strains to a new serotype: serotype 9, with strain CVJ 13261 as the type strain.In addition to the serotype-specific capsular antigens, capsular antigen of serotype 1 (strain 4074) could be demonstrated in the 10 strains by means of gel diffusion analyses.In cross protection studies it was shown that the antigenic determinants shared by serotypes 9 and 1 were unable to yield a sufficient protection against disease. Thus, parenteral immunization with a killed 6-h culture of serotype 9 did not afford an acceptable protection against challenge with serotype 1 since only 3 of the 5 vaccinates were protected. The reverse experiment showed that parenteral immunization with serotype 1 only protected 1 out of 4 vaccinates.     

鸡新城疫-传染性支气管炎(M41株)二联灭活苗的免疫保护期测定

传染性支气管炎能引起鸡的急性、高度接触性的呼吸道、消化道和泌尿生殖道疾病,对我国养鸡业构成严重威胁。而新城疫也是危害我国养鸡业的重要传染病。疫苗免疫是公认的预防这2种疫病的方法。本研究利用自制的3批ND-IB二联灭活疫苗,分别对28日龄易感雏鸡和120日龄开产前母鸡进行免疫,利用HI试验测出试验鸡群的抗体值。结果表明28日龄易感雏鸡在2个月内,开产前母鸡在3个月内均受到有效保护,为本批新 支二联疫苗的实际临床免疫接种提供了依据。      

纳米氢氧化铝吸附禽流感病毒灭活疫苗的研制及其对肉鸡抗体效价的影响

自制纳米氢氧化铝佐剂,通过吸附H5N1灭活抗原,制备了纳米铝佐剂疫苗,按照中华人民共和国农业行业高致病性禽流感免疫技术规范标准,免疫肉鸡。经检测发现纳米铝佐剂疫苗组肉鸡产生有效保护抗体时间较油佐剂疫苗和常规铝佐剂疫苗提前3d和7d,抗体峰值达到时间较油佐剂疫苗和常规铝佐剂疫苗提前14d。结果表明,纳米氢氧化铝作为高致病性禽流感H5N1的免疫佐剂,可以更早的刺激动物产生有效保护抗体,纳米铝佐剂禽流感疫苗具有广泛的应用价值。     

不同免疫途径对商品蛋雏鸡新城疫黏膜及血清抗体的影响

通过不同的免疫途径对商品蛋雏鸡进行免疫,探讨不同的免疫途径对商品蛋雏鸡新城疫(Newcastle disease,ND)黏膜抗体及血清抗体的影响。结果表明,同时用新城疫弱毒疫苗免疫后,不同的免疫途径产生的新城疫黏膜抗体及血清抗体效价有较大差异。采用喷雾法于3日龄首免,15日龄二免,25日龄三免,鸡体产生保护水平(6 log2)以上的ND黏膜抗体和血清抗体最快、抗体水平最高、维持时间最长、总体免疫效果最好,而采用饮水免疫的试验组产生的ND黏膜抗体和血清抗体水平均不高,总体免疫效果最差。     

营养因素对肉鸡肠道黏膜免疫的影响

根据肠道黏膜免疫的重要性,结合肉鸡肠道结构特点,阐述日粮中的主要营养因素对肉鸡肠道黏膜免疫的影响,并展开讨论。