猪瘟疫苗不同剂量对猪免疫攻毒效果试验报告

本试验根据近年来湖南农村猪瘟疫苗使用头剂量的变化，在室内、室外分别对猪接种不同剂量猪瘟弱毒乳兔苗和牛睾细胞苗，免疫期１０６￣１３０天攻击石门系猪瘟强毒，其室内接种组攻毒结果：猪瘟乳兔苗头剂量０．５ｍｌ１５０个免疫量，保护率１００％（５／５）；头剂量１．０ｍｌ１５０个免疫量保护率１００％（５／５）；头剂量１．０ｍｌ３００个免疫量保护率１００％（４／４）。牛睾国胞苗头剂量０．５ｍｌ３００个免疫量保护率     

蛋鸡开产前后适宜钙水平的研究

选育发育正常的１３ 周龄罗曼商品蛋鸡６００ 只， 随机分为３ 组， 每组２００ 只， 每组４ 个重复。７ 天预试期，其间调整各组鸡使组间体重差异不显著；正式期９８ 天。３ 组鸡日粮组成及营养水平和饲养条件相同，干粉料每天饲喂两次，自由采食及饮水。各组日粮钙水平随产蛋率的增加而增加。试Ⅰ组１４ ～１８ 周龄为２ ．０ ％ ，１８ 周龄～５ ％ 产蛋率为２ ．０ ％ ，５ ％ ～５０ ％ 产蛋率为３ ．４ ％ ，＞ ５０ ％ 产蛋率为３ ．４ ％ ； 试Ⅱ组四个阶段日粮钙水平分别为：０ ．９ ％ 、２ ．０ ％ 、３ ．４ ％ 及３ ．４ ％ ；对照组分别为０ ．９ ％ 、２ ．０ ％ 、２ ．０ ％ 及３ ．４ ％ 。试验期间每日观察鸡的精神状态、采食及粪便情况；每日按组别测定采食量、产蛋率等；每７ 天测一次蛋壳厚度及蛋重。结果表明：①试验期间两试验组鸡健康状况良好，对照组有２ 只鸡瘫痪。②产蛋率达５ ％ 的日龄三组间接近； 达５０ ％ 产蛋率的日龄对照组稍迟于两试验组； 达９０ ％ 产蛋率的日龄试Ⅰ组早于试Ⅱ组２ 天，早于对照组４ 天。③试验期间三组平均产蛋率分别为： ５２ ．４ ％ 、５６ ．３ ％ 及５４ ．７ ％ 、试Ⅰ组与试Ⅱ组差异显著，与对照组差异极显著，试Ⅱ组与对照组差异显著     

禽霍乱蜂胶灭活苗对鸭的田间试验和区域试验

应用禽霍乱蜂胶灭活疫苗对鸭进行田间免疫试验和扩大区域试验证实，该苗安全性能良好，对鸭的生产性能无明显影响，紧急免疫能在３５天内控制疫情。田间试验用１０ｍｌ、１５ｍｌ剂量免疫的鸭，禽霍乱死亡率分别为１８１％、０８８％，出现发病死亡的时间前者比后者早。与禽霍乱弱毒苗免疫结果对比，蜂胶苗组死亡率为１３４％，弱毒苗组为３５９％，非免疫组为５１１％；非禽霍乱死亡率蜂胶苗组为３２１％，弱毒苗组为６４６％，非免疫组为９０５％。     

猪传染性胃肠炎与猪流行性腹泻穴位针刺免疫的研究

以猪传染性胃肠炎（ＴＧＥ）弱毒疫苗经与胃肠道疾病相关的足阳明胃经６个穴位和督脉经后海穴位共７个穴位的穴位免疫筛选试验，证明后海穴接种为３／３保护，是首选的接种穴位。以后海穴取代ＴＧＥ苗原鼻内途径的第二次接种，免疫４头妊娠母猪，对所产仔猪的保护数为３７／４１。以小剂量０．１ｍｌ及０．２ｍｌ后海穴接种３日龄仔猪，保护率分别为６０．５３％及１００％，而口服０．１ｍｌ只保护６．６７％。针刺１．５ｃｍ及３．     

猪流行性腹泻病毒适应Vero细胞培养及以传代细胞毒制备氢氧化铝灭活疫苗免疫效力试验

采用在病毒培养液中加５～１０μｇ／ｍｌ胰酶的培养方法，将猪流行性腹泻病毒（ＰＥＤＶ）ＣＶ＿（７７７）适应于Ｖｅｒｏ细胞，并传４５代．细胞病变规律．经免疫荧光检查阳性，电镜观察可见典型冠状病毒粒子，猪传染性胃肠炎（ＴＧＥ）免疾荧光检查阴性，猪流行性腹泻（ＰＥＤ）血清可抑制细胞病变（ＣＰＥ）．ＰＥＤＶＣＶ＿（７７７）毒株１１、２５、２８、４０及４４代传代毒的毒价分别为１０￣（３．５）、１０￣（５．５）、１０￣（６．５）、１０￣（７．０）和１０￣（７．０）ＴＣＩＤ＿（５０）／０．３ｍｌ。以１１、２１及２２代的毒１０ｍｌ头口服接种未吃初乳仔猪，可使之典型发病，免疫荧光及电镜观察均呈阳性．分别以２５、２８及３１代毒０．５ｍｌ／头、１ｍｌ／头、２ｍｌ／头口服接种３日龄仔猪１８头．除０．５ｍｌ组有１头反应外，均未发病，攻毒试验的总保护率为８７．５％，对照组１００％发病．以２８代毒制备氢氧化铝灭活苗，后海穴位接种，主动免疫组８５．１９％保护，被动免疫组８５％保护，对照组１００％及９２．３％发病．     

肉鸡心包积水综合征病原的水平传播

用三个对比试验（１、２和３）研究了心包积水综合征（ＨＰＳ）病原的水平传播率．其中６０、５０和７０只鸡组中分别有５、３和７只鸡进行人工感染，且饲养密度分别为０．８３、１．００和０．７１平方英尺／只。在每个试验中同时饲养一组对照鸡。非参数残存函数与资料相符，并用Ｍａｎｔｅｌ—Ｃｏｘ和Ｂｒｅｓｌｏｗ进行比较。在试验１、２和３中ＨＰＳ的平均潜伏期分别为９．５、１３．０和１４．５天，日平均死亡率分别为３．４、４．５、和４．５％。累计死亡率分别为４０、５４和５５．７％。这些结果之间无显著差异。     

喂大快对产蛋鸡后期生产性能的影响

选择４６周龄海兰褐蛋鸡１２００只，随机分为３组，每组４００只。Ａ组为对照组，Ｂ组为试验Ⅰ组，基础日粮加０．２％喂大快，Ｃ组为试验Ⅱ组，基础日粮加４．３％玉米，加０．５％的芝麻粕，减去０．５％动物蛋白及１．５％的油和３％沸石粉，再加０．２％的喂大快，营养水平与对照组接近。饲喂４周，结果表明：试验Ⅰ组比对照组平均蛋重提高７．８９％，料蛋比下降６．８５％，试验Ⅱ组比对照组平均蛋重提高７．０３％，料蛋比下     

花粉多糖对新城疫弱毒苗免疫效果影响

当鸡新城疫母源抗体低于２ｌｏｇ２时，３种５％的花粉多糖水溶液与克隆３０弱毒苗共同免疫７日龄小鸡，免疫后在不同的天数监测其ＨＩ抗本铲价，结果表明，５％的玉米花粉多糖具有明显增强体液免疫效果，且作用最好，油菜花粉多糖次之，荞麦花粉多糖再次之，３个不同剂量中以０．１ｍｌ效果最佳。与０．２ｍｌ．０．５ｍｌ相比，经ｔ检验，差异显著。     

中西药复方制剂防治鸡新城疫的效力试验

以板兰根、大青叶、黄连等中药制成粉剂，再配以病毒灵等制成“抗瘟Ⅰ号”，进行人工诱发鸡新城疫的效力试验，按０．５％、１％、２％浓度混饲给药后，鸡新城疫防治的痊愈率分别是７６．７％、８６．７％、９３．３％，死亡率分别为２３．３％、１４．４％、６．６％，而感染对照组的自愈率、死亡率分别为２０％和８０％。     

花粉多糖对新城疫弱毒苗免疫效果影响--玉米、油菜、荞麦3种花粉多糖作用的比较

当鸡新城疫母源抗体低于２ｌｏｇ２时，３种５％的花粉多糖水溶液与克隆３０弱毒苗共同免疫７日龄小鸡，免疫后在不同的天数监测其ＨＩ抗体效价，结果表明，５％的玉米花粉多糖具有明显增强体液免疫效果，且作用最好，油菜花粉多糖次之，荞麦花粉多糖再次之。３个不同剂量中以０．１ｍｌ（其中含糖５ｍｇ）效果最佳。与０．２ｍｌ（含糖量１０ｍｇ），０．０５ｍｌ（含糖量２．５ｍｇ）相比，经ｔ检验，差异显著（Ｐ＜０．０５）。     

Onset and duration of immunity and minimum dosage with CU cholera vaccine in turkeys via drinking water

Growing turkeys were partly protected against fowl cholera 4 days after vaccination with the live Clemson University (CU) strain of Pasteurella multocida administered in drinking water, and they were highly protected from 1 to 4 weeks after vaccination. The commercially available lyophilized vaccine and the freshly cultured vaccine of the CU strain did not differ in the level of immunity induced. Immunity was relatively high in turkeys vaccinated with 1:2 and 1:4 dilutions of the recommended dosage (4 X 10(8) P. multocida) but was significantly (P less than 0.05) lower in turkeys vaccinated with a 1:8 dilution of the recommended dosage. Immunity continued for 13 weeks after the last vaccination in turkeys vaccinated twice 3 weeks apart, but it persisted for only 8 weeks in those vaccinated only once.     

Fowl cholera immunity induced by various vaccines in broiler minibreeder chickens determined by enzyme-linked immunosorbent assay

Broiler minibreeder hens were vaccinated for protection against fowl cholera at 12 and 21 weeks of age using several vaccination schemes, which included a live Pasteurella multocida (CU strain) vaccine, two commercial polyvalent fowl cholera oil-based bacterins, and two experimentally prepared polyvalent oil-based bacterins. Some treatment groups received only live or killed vaccines, whereas others received a live vaccine at 12 weeks followed by a killed product at 21 weeks. At 42 weeks of age, all birds that received the live CU vaccine twice or once followed by a bacterin survived challenge. Birds that received killed vaccines only were significantly less protected but still showed a respectable survival rate of 86%. All unvaccinated controls died within 72 hr after challenge. At 72 weeks of age, overall protection was lower than that at 42 weeks, regardless of vaccination treatment. Antibody titers were usually higher in birds that received bacterins than in those receiving live vaccines, yet overall protection was still greater in those birds that received the live cholera vaccine twice.     

Fowl cholera: influence of Bordetella avium on vaccinal immunity of turkeys to Pasteurella multocida

Turkeys exposed to Bordetella avium were vaccinated against fowl cholera with live Pasteurella multocida vaccine. Previous exposure to B. avium resulted in impairment of systemic immunity conferred by the vaccine: 86% of the vaccinated turkeys exposed to B. avium at 1 day old developed lesions or died of fowl cholera after challenge at 15 weeks old with virulent P. multocida. Of vaccinated turkeys not previously exposed to B. avium, only 26% had lesions or died of fowl cholera.     

Efficacy of an inactivated vaccine against hydropericardium syndrome in broilers

Field trials were used to assess the efficacy of an inactivated vaccine against hydropericardium syndrome in broiler chickens. A single vaccination at 10 to 12 days old was effective for the control of the syndrome; mortality in the vaccinated birds was 0.52 per cent compared with 5.34 per cent in unvaccinated birds kept at the same premises. Vaccination was also effective when carried out in the face of an outbreak; mortality in the vaccinated infected birds was 2.33 per cent compared with 10.27 per cent in unvaccinated infected birds. The data indicate that a formalinised vaccine prepared from the liver of experimentally infected birds could be used for the control of hydropericardium syndrome.     

Advancement in vaccination against Newcastle disease: recombinant HVT NDV provides high clinical protection and reduces challenge virus shedding with the absence of vaccine reactions

Newcastle disease (ND) is a highly contagious disease of chickens causing significant economic losses worldwide. Due to the limitation in their efficacy, current vaccination strategies against ND need improvements. This study aimed to evaluate a new-generation ND vaccine for its efficacy in providing clinical protection and reducing virus shedding after challenge. Broiler chickens were vaccinated in ovo or subcutaneously at hatch with a turkey herpesvirus-based recombinant vaccine (rHVT) expressing a key protective antigen (F glycoprotein) of Newcastle disease virus (NDV). Groups of birds were challenged at 20, 27, and 40 days of age with a genotype V viscerotropic velogenic NDV strain. Protection was 57% and 81%, 100% and 95%, and 100% and 100% after the subsequent challenges in the in ovo and subcutaneously vaccinated chickens, respectively. Humoral immune response to vaccination could be detected from 3-4 wk of age. Challenge virus shedding was lower and gradually decreased over time in the vaccinated birds compared to the unvaccinated control chickens. In spite of the phylogenetic distance between the NDV F gene inserted into the vector vaccine and the challenge virus (genotype I and V, respectively), the rHVT NDV vaccine provided good clinical protection and significantly reduced challenge virus shedding.     

Laryngotracheitis in chickens: infection studies and the efficacy of a tissue-culture vaccine in chicks less than four weeks old

Challenge studies using the standard National Veterinary Services Laboratory laryngotracheitis (LT) challenge virus (Log 10(6.7) EID50 per ml) were conducted to assess the presence of maternal protection in chicks of various ages (1, 7, 14, 21, and 28 days). Chicks from vaccinated and unvaccinated breeders were challenged by intratracheal inoculation. Chicks of all these ages irrespective of origin were susceptible to infection. Similarly derived chicks were vaccinated by eyedrop with a commercially available tissue-culture vaccine. Chicks vaccinated at 21 and 28 days were adequately protected from challenge (77-94% protection), whereas less than 60% of chicks vaccinated at 1, 7, or 14 days were protected.     

Vaccination of chickens using raw rice coated with novel trehalose nano-organogels containing Newcastle disease (strain I-2) vaccine

The formulation and evaluation of trehalose nano-organogels for storage and oral delivery of Newcastle disease (ND) strain I-2 vaccine to chickens were carried out in this study. Trehalose sugar was blended with vegetable oil to form nano-organogels where trehalose also acted as a stabilizer against thermal inactivation of I-2 ND virus. Results from infectivity titration assay indicated that the titre of 10^7.5 EID₅₀/0.1 mL was maintained after 12 weeks of storage of nano-organogel I-2 vaccine at ambient room temperature. Serology results showed that 33% chickens which were vaccinated with nano-organogel I-2 vaccine after 14 days had HI antibody titres of ≥ 3.0 log₂ with GMT of 2.3. Moreover, results showed 100% of chickens vaccinated with nano-organogel I-2 vaccine had the mean antibody titres of 3.4 and 3.7 log₂ at 21 and 28 days after vaccination, respectively. All vaccinated chickens (100%) survived the challenge of virulent ND virus whereas all unvaccinated chickens succumbed to challenge and died of signs consistent with ND. The findings from this study showed that the nano-organogel I-2 vaccine was stable at room temperature, safe and produced protective antibody response in vaccinated chickens. Moreover the nano-organogel I-2 vaccine was used for oral administration and hence is suitable for mass vaccination. However, optimization of the formulation of trehalose nano-organogel vaccine is required in order to achieve its application potentials.     

The resistance of meat chickens vaccinated by aerosol with a live V4 Newcastle disease virus vaccine in the field to challenge with a velogenic Newcastle disease virus

Meat chickens housed on a commercial broiler farm in Australia were vaccinated once at 10 to 11 days-of-age by aerosol with live V4 Newcastle disease virus (NDV) vaccine. Groups of vaccinated and unvaccinated birds were flown to Malaysia, where they were challenged with a virulent strain of NDV. Survival rates in vaccinated chickens challenged 7, 14, 21 or 31 d after vaccination were 0.47, 0.77, 0.97 and 0.92, respectively. All unvaccinated chickens died due to Newcastle disease (ND) following challenge. Chickens in Australia and Malaysia were bled and the serums tested for haemagglutination-inhibiting (HI) antibody to NDV. Many vaccinated birds with no detectable antibody, and all birds with a log2 titre of 2 or greater, survived challenge. The results showed that this V4 vaccine induced protective immunity in a significant proportion of chickens within 7 d of mass aerosol vaccination. This early immunity occurred in the absence of detectable circulating HI antibody. Non-HI antibody mediated immunity continued to provide protection up to 31 d after vaccination. Almost all vaccinated birds were protected within 3 w of vaccination. It is concluded that the V4 vaccine is efficacious and could be useful during an outbreak of virulent ND in Australia.     

Experimental infections with fowl pox in chickens

Seven groups of chickens were challenged with a field isolate of fowl pox virus at 18 weeks old. The birds in the groups that had been vaccinated 3 weeks previously with fowl pox vaccinates showed no signs of disease. Birds which had not been vaccinated against fowl pox developed upper respiratory disease after challenge, and some birds had diphtheritic tracheitis and laryngitis which appeared identical to that commonly seen under field conditions. Seven days after challenge, fowl pox virus was recovered from the tracheas of unvaccinated birds, but not from the vaccinated ones.

Intercurrent Mycoplasma gallisepticum infection appeared to extend slightly the period of respiratory disease but was not essential for development of the diphtheritic lesion.     

Immunogenicity of an Escherichia coli multivalent pilus vaccine in chickens

Immunogenicity of an oil-emulsified Escherichia coli multivalent pilus vaccine was evaluated in 4-week-old chickens. The vaccine contained 180 micrograms of pilus protein from each of serotypes O1 and O78 and 170 micrograms of pilus protein from serotype O2. Chickens were vaccinated twice subcutaneously at 4 and 6 weeks old and challenged via the posterior thoracic air sac with E. coli serotype O1, O2, or O78 2 weeks after the last vaccination. Unvaccinated challenged chickens suffered 8% to 26% mortality; no vaccinated chickens died. Vaccinated chickens had very mild gross lesions in the air sacs, livers, and pericardial sacs and eliminated E. coli more efficiently than the unvaccinated challenged chickens. The results showed that a multivalent pilus vaccine protects chickens against active respiratory infection.