鸡传染性法氏囊病免疫程序初探

用四种不同免疫程序免疫肉雏鸡和蛋雏鸡Ａ，分别于３、１０、２１日龄用ＩＢＤ弱毒疫苗饮水免疫Ｂ，于１４、２８日龄用ＩＢＤ弱毒苗饮水Ｃ于３日龄弱毒苗饮水，１０日龄用没乳剂组织灭活苗下接种Ｄ１０日龄用油乳剂灭活苗皮下接种，试验表明，Ｃ、Ｄ两种免疫程序效果极佳，免疫鸡地２１日龄地就能检测出ＡＧＰ抗体，以后抗体上升较快，６０日龄时达高峰，其ＡＧＰ效价最高达１：２＾８．４３，ＲＰＨＩ达１：２＾１６．４３，蛋鸡至     

鸡用天然缓释免疫增强剂的研究：天然缓释免疫增强剂对IBD等4？…

对７日龄艾维茵雏鸡投服天然缓释免疫增强剂１丸,１０日龄时分别用ＩＢＤ、ＮＤ、ＩＢ弱毒疫苗及ＮＤ油乳剂灭活苗免疫;免疫后７、１５、２５、３５一５５ｄ定期检测抗体效价;弱毒苗免疫后３５ｄ、灭活苗免疫后５５ｄ分别用强毒攻击。结果各试验组抗体效价显著高于对照组,试验组攻毒保护率提高１６．７￣３３．３个百分点。表明该缓释免疫增强剂能显著增强雏鸡的免疫应答,提高疫苗的免疫效力。     

新城疫病毒弱毒疫苗的免疫研究

新城疫病毒长春株（ＮＤＶ ＣＣ株）经生物学及分子生物学特性研究证明为新城疫病毒弱毒株,以ＮＤＶ ＣＣ毒株制成弱毒疫苗,采用饮水、滴鼻和肌肉注射免疫等方式,分别免疫７日龄雏鸡,免疫鸡未出现不良反应。免疫后７ｄＨＩ效价为２＾５以上,６０ｄ后均能维持较高的ＨＩ值,免疫后１４ｄ用ＮＤＶ强毒攻击,其保护率可达到１００％（１０／１０）。     

鸡传染性法氏囊病免疫程序初探

用四种不同的免疫程序免疫肉雏鸡和蛋雏鸡：Ａ，分别于３、１０、２１日龄用ＩＢＤ弱毒疫苗饮水免疫；Ｂ，于１４、２８日龄用ＩＢＤ弱毒苗饮水；Ｃ，于３日龄弱毒苗饮水、１０日龄用油乳剂组织灭活苗皮下接种；Ｄ，１０日龄用油乳剂灭活苗皮下接种。试验表明，Ｃ、Ｄ两种免疫程序效果极佳，免疫鸡于２１日龄时就能检测出ＡＧＰ抗体，以后抗体上升较快，６０日龄时达高峰，其ＡＧＰ效价最高达１∶２８．４３、ＲＰＨＩ达１∶２１６．４３，蛋鸡至１２０日龄时，血清中仍可维持较高水平抗体，攻毒结果表明，各个日龄试验鸡对ＩＢＤ野毒攻击均具有１００％的保护率。而Ａ、Ｂ两种免疫程序效果不佳，只能产生低水平抗体，各个日龄试验鸡对野毒攻击均未获完全保护。     

新城疫与传染性法氏囊病疫苗对雏鸡联合免疫的研究

将１１４只１１日龄海赛克斯褐公鸡随机分成５组：Ⅰ组为空白对照，Ⅱ组用新城疫（ＮＤ）弱毒苗和ＮＤ油佐剂灭活苗同时免疫，Ⅲ组用传染性法氏囊病（ＩＢＤ）地方毒株油佐剂灭活苗免疫，Ⅳ组用ＮＤ弱毒苗、ＮＤ油佐剂灭活苗、ＩＢＤ地方毒株油佐剂灭活苗同时免疫，Ⅴ组在Ⅳ组的基础上增加ＩＢＤ弱毒苗免疫。５组鸡分别隔离饲养，定期测定血清ＮＤＨＩ效价与ＩＢＤ琼扩效价。选择时机用强毒攻击，观察各组鸡的保护情况。结果：（１）Ⅱ、Ⅳ、Ⅴ组鸡均能很好地抵抗ＮＤＶ强毒的攻击，Ⅲ、Ⅳ、Ⅴ组鸡无论对ＩＢＤＶ人工感染，还是自然感染，均有坚强的保护力；（２）ＩＢＤ地方毒株油佐剂灭活疫苗不干扰ＮＤ疫苗的免疫应答；（３）ＩＢＤ弱毒苗对ＮＤ疫苗的免疫应答有一定影响，在免疫初期能促进机体尽快对ＮＤ疫苗产生应答，但后期ＮＤ疫苗的ＨＩ抗体降低较快；（４）ＮＤ疫苗对ＩＢＤ疫苗的免疫效果无显著影响。作者提出，对雏鸡首免（无论有、无母源抗体）可采用ＮＤ弱毒苗＋ＮＤ油佐剂灭活苗＋ＩＢＤ（地方毒株）油佐剂灭活苗同时进行免疫，至少可以保护到上笼后或开产前免受ＮＤＶ和ＩＢＤＶ的感染，既简化了免疫程序，又可减少对鸡群的应激，值得推广应用。     

雏鸡新城疫母源抗体保护力及Clone—30弱毒疫苗点眼免疫效果观察试验

本试验对不同日龄,不同新城疫母源抗体水平的艾维茵商品肉鸡进行了新城疫（ＮＤ）攻毒,同时对经Ｃｌｏｎｅ－３０弱毒疫苗１次点眼免疫后的鸡只攻毒,并对每只鸡的抗体水平作跟踪监测,结果表明,非经免疫的,１０日龄以内的雏鸡,只有在母源抗体水平很高（ＮＤ－ＨＩ效价〉６Ｌｏｇ２）的情况下才能抵抗瓣城疫强毒的攻击,母源抗体较低的鸡只（抗体效价≤６Ｌｏｇ２）大多数不能抵抗新城疫强毒的攻击,雏鸡经Ｃｌｏｎｅ－３０弱毒     

雏鸡新城疫母源抗体保护力及Clone-30弱毒疫苗点眼免疫效果观察试验

本试验对不同日龄、不同新城疫母源抗体水平的艾维茵商品肉鸡进行新城疫（ＮＤ）攻毒,同时对经Ｃｌｏｎｅ－３０弱毒疫苗１次点眼免疫后的鸡只攻毒,并对每只鸡的抗体水平作跟踪监测。结果表明,非经免疫的、１０日龄以内的雏鸡,只有在母源抗体水平很高（ＮＤ－ＨＩ效价＞６Ｌｏｇ２）的情况下才能抵抗新城疫强毒的攻击;母源抗体较低的鸡只（抗体效价６Ｌｏｇ２）大多数不能抵抗新城疫强毒的攻击。雏鸡经Ｃｌｏｎｅ－３０弱毒疫苗点眼免疫１周后,尽管其体液抗体水平很低,但在一定时期内可获得较好的保护力。     

鸡结膜结合淋巴组织（CALT）对新城疫疫苗点眼免疫应答

１８０只１日龄公雏平均分成Ａ、Ｂ、Ｃ三组。Ａ组于１日龄手术切除下眼睑结膜。Ａ、Ｂ两组于１０日龄和２０日龄用鸡新城疫Ⅱ系（ＮＤⅡ）弱毒疫苗点眼首免和二免，Ｃ组为对照组。定期收集泪液、血清、ＣＡＬＴ和哈德氏腺，比较观察其抗体ＨＩ效价消长规律与免疫组织细胞变化特点。结果，Ｃ组非免鸡泪液ＨＩ效价比血清ＨＩ效价稍低，１０至３４日龄均呈直线下降，３４至４８日龄维持在极低的水平上（１．２￣２Ｌｏｇ２）。Ｂ组点眼     

新城疫鸡胚免疫的研究

本文应用鸡新城疫（ＮＤ）Ⅱ系和Ｖ４弱毒疫苗分别气室接种不同孵化日龄鸡胚,出雏后计算其孵化率并在不同日龄测定血清ＨＩ抗体效价,结果表明,ＮＤⅡ系和Ｖ４疫苗１∶１０稀释,于１８、１９胚龄气室接种,对孵化率无显著影响（Ｐ＞００５）,两种疫苗间也无明显差异（Ｐ＞００５）,均能产生良好的免疫保护力。     

免疫鸡群感染新城疫强毒后的排毒规律

将经过２次新城疫（ＮＤ）基础免疫的ＳＰＦ鸡,随机分成５组,每组８只,在６０日龄时分别用Ｆ４８Ｅ８、Ｔｅｘａｓ、Ｈｅｒｔ３３ＮＤ强毒和Ｌａｓｏｔａ弱毒经口腔接种０．２５ｍＬ／只,１２ｈ后采取泄殖腔棉拭,利用ＮＤ强毒快速诊断试剂盒进行排毒的动态监测,并在攻毒前期、中期、后期测定各试验组ＳＰＦ鸡的ＨＩ效价。试验第３天开始排毒,２０ｄ结束,其间在６～７ｄ和１１～１３ｄ出现２次排毒高峰。ＨＩ抗体在初期先是降低１个滴度,后期开始升高而且离散度不断增大。     

Immunosuppressive effect of infectious bursal disease virus strains of variable virulence for chickens.

Infection of chicks with attenuated Lp and Sp clones of the RF-1 strain of infectious bursal disease virus was shown to exert no immunosuppressive effect, whereas the parent strain RF-1tc and the original virulent strain RF-1wt were immunosuppressive. One-day-old chicks infected with Lp and Sp clones showed no suppression of immunological response to live Newcastle disease vaccines B1 and TCND, and to bivalent infectious coryza vaccine. On the other hand, infection with RF-1tc or RF-1wt strains was immunosuppressive for these vaccines. The immunosuppressive effect of RF-1tc and RF-1wt strains was more pronounced for infectious coryza vaccine and B1 vaccine than for TCND vaccine. The immunosuppressive effect of RF-1tc and RF-1wt strains was lower when chicks were infected with these strains at the age of 21 days than when they were infected at one day of age.     

Measurement of immunosuppression in chickens caused by infectious bursal disease vaccines using Brucella abortus strain 19.

The serological response of chicks to Brucella abortus strain 19 was monitored over a period of seven weeks to assess the degree of immunosuppression caused by vaccination at one day of age with two infectious bursal disease vaccines. One of the vacy. This vaccine caused severe immunosuppression judged by the minimal serological response following B abortus inoculation. The test also detected a significant delay caused by the other vaccine in the development of the serological response but the maximum titre was not significantly different from that in chicks which had received no infectious bursal disease vaccine.     

Impact of BSE on Livestock Production System

A total of 240 unvaccinated day-old broiler chicks, which had been found to be negative for antibodies against FAV-4, were divided into four groups of 60 chicks each. Group A was fed aflatoxin at 1 ppm from 7 days to 7 weeks of age. Group V was infected intra-abdominally at 14 days of age with 0.2 ml of FAV-4, having a titre of 10^5.5 TCID₅₀ per 0.2 ml. The combined group AV was given the aflatoxin and infected with FAV-4. The fourth group C served as the control. More pronounced clinical signs, a higher mortality rate (56.7%), and reductions in body weight gain and in the organ to body weight ratios of the bursa and spleen were recorded in group AV. A significant (p<0.01) reduction in the HI antibody titre following vaccination against Newcastle disease, and of skin thickness in the delayed hypersensitivity test following sensitization with DNCB, indicated an additive immunosuppressive effect from aflatoxin and FAV-4 on the humoral and cell-mediated immune responses in group AV compared to groups A and V. Microscopically, marked depletion and degeneration of lymphocytes in the thymus, bursa, spleen and caecal tonsils were observed in group AV up to 5 weeks PI.     

Consequence of Cryptosporidiosis on the immune response of vaccinated broiler chickens against Newcastle disease and/or avian influenza

The consequence of cryptosporidiosis on the immune response of vaccinated chickens against Newcastle disease and/or avian influenza was studied by using 240, 1 day old, male, white Hy-Line chicks and divided into 8 groups and subgroups. Each group or subgroup was consisting of 30 chicks (15?×?2 replicates). The first and second groups were kept as unvaccinated control, G1uninfected and G2 infected. G3, G4 and G5 contained 2 subgroups A&B (G3A, G3B, G4A, G4B, G5A and G5B). Chicks of subgroup A were vaccinated only while chicks of subgroup B were infected and vaccinated. These chicks were orally inoculated with 5?×?10⁵ oocysts of Cryptosporidium baileyi (C. baileyi) at 2 days of age. Chickens were vaccinated intraocular with live Newcastle disease (ND) vaccine (Hitchner on day 7th and LaSota on day 17th of chicken life) (G3) or vaccinated by subcutaneous route with Volvac®- H5N2- AI vaccine on day 10 of chicken life (G4). Last group (G5) was infected similarly and vaccinated with ND and AI vaccines with the same day, dose and route of vaccination for each one. Random blood samples were collected for 3 weeks post-vaccination for investigation of humoral immune response against Newcastle and/or avian influenza vaccines by the haemagglutination inhibition (HI) test. The results showed that H5N2 vaccine at day 10 of chicken life is effective in chickens indicated by the geometric mean of HI titer against AI virus. The findings of this study showed that the infection with Cryptosporidia in the broiler chicken has a depressive effect on the immune status of the birds vaccinated against ND and/or AI vaccination. Moreover, the obtained protection rates against challenge with virulent ND virus observed to be parallel to the results of HI- test. Also, by using 2 different antigens (one commercial and field prepared antigen) to avian influenza virus, lower Geometric mean (GM) HI titer were appeared in infected and vaccinated group than vaccinated group only. A study of the relative lymphoid organs weight such as bursa of Fabricius from the experimental chicks indicated that those organs were comparable between the groups infected-vaccinated and vaccinated only. Non significant variations in final live weight between uninfected control and infected groups were indicated. Also, H5N2-AI vaccination at 10 days old did not affect the final live weight. ND and/or AI Vaccination could not be a substitute to application of good hygienic measures and fecal examination of the birds especially for protozoal diseases such as cryptosporidiosis. It could be concluded that cryptosporidiosis could be one cause of ND and/or AI vaccination failure in poultry farms.     

Gel-Bead Delivery of Eimeria oocysts protects chickens against coccidiosis

Vaccines composed of either virulent or attenuated Eimeria spp. oocysts have been developed as an alternative to medication of feed with ionophore drugs or synthetic chemicals. The purpose of this study was to evaluate the use of gel-beads containing a mixture of Eimeria acervulina, Eimeria maxima, and Eimeria tenella oocysts as a vaccine against coccidiosis. Newly hatched chicks (Gallus gallus domesticus) were either sprayed with an aqueous suspension of Eimeria oocysts or were allowed to ingest feed containing Eimeria oocysts-incorporated gel-beads. Control day-old chicks were given an equivalent number of Eimeria oocysts (10(4) total) by oral gavage. After 3 days, chicks were randomly assigned to individual cages, and feces were collected between days 5 and 8 postinfection. All samples were processed for total Eimeria oocysts. At 4 wk of age, all chickens and a control nonimmunized group received a high-dose E acervulina, E maxima, and E. tenella challenge infection. Oocyst excretion by chicks fed gel-beads or inoculated by oral gavage was 10- to 100-fold greater than that of chicks spray-vaccinated with the Eimeria oocysts mixture (log 6.3-6.6 vs. log 4.8). Subsequent protection against challenge as measured by weight gain and feed conversion efficiency was significantly greater (P < 0.05) in gel-bead and oral gavage groups compared with spray-vaccinated or nonimmunized groups. Also, gel-bead and oral gavage groups showed no significant difference (P > 0.05) in weight gain and feed conversion efficiency compared with nonchallenged controls. These findings indicate that incorporation of Eimeria spp. oocysts in gel-beads may represent an effective way to deliver live oocyst vaccines to day-old chicks for preventing subsequent outbreaks of coccidiosis in the field.     

Effect of dietary probiotic,prebiotic and synbiotic supplementation on performance,immune responses,intestinal morphology and bacterial populations in broilers

This study was conducted to investigate the effects of probiotic (Primalac), prebiotic (TechnoMos) and synbiotic (Primalac + TechnoMos) supplementation on performance, immune responses, intestinal morphology and bacterial populations of ileum in broilers. A total of 240 one‐day‐old broiler chicks were randomly divided into four treatment groups which included 60 birds. Control group did not receive any treatment. The chicks in the second, third and fourth groups were fed probiotic (0.9 g/kg), prebiotic (0.9 g/kg) and probiotic (0.9 g/kg) plus probiotic (0.9 g/kg; synbiotic), respectively, at entire period. Daily feed intake, daily weight gain and feed conversion ratio were evaluated. The birds were immunized by sheep red blood cell (SRBC) on days 12 and 29 of age and serum antibody titres were measured on days 28, 35 and 42. Newcastle vaccines administered on days 9, 18 and 27 to chicks and blood samples were collected on day 42. Intestinal morphometric assessment and enumeration of intestinal bacterial populations were performed on day 42. The results indicated that consumption of probiotic, prebiotic and synbiotic had no significant effect on daily feed intake, daily body weight gain, feed conversion ratio, carcass traits, intestinal morphology and bacterial populations of ileum (p > 0.05). Consumption of prebiotic increased total and IgM anti‐SRBC titres on days 28 and 42 and antibody titre against Newcastle virus disease on day 42 (p < 0.05). Synbiotic increased only total anti‐SRBC on day 28 (p < 0.05). It is concluded that consumption of prebiotic increased humoral immunity in broilers. Therefore, supplementation of diet with prebiotic for improvement of humoral immune responses is superior to synbiotic supplementation.     

Incubation and maternal behaviour in domestic hens: influence of the presence of chicks on circulating luteinising hormone, prolactin and oestradiol and on behaviour

1. The consequences of the adoption of chicks and their subsequent removal on behaviour and plasma hormone concentrations of incubating hens were investigated. Birds were divided into two group: in group A, incubating hens were given chicks for 11 d; in group B chicks were left with the hens for 3 d only. 2. Incubating hens given chicks immediately showed maternal responses. The introduction of chicks induced a gradual nest desertion. Their removal stopped nest desertion temporarily on day 4 in group B hens. 3. Plasma prolactin concentrations fell one day after introduction of chicks and continued to decline for about one week in group A hens, although there was no further significant decrease in group B hens. Circulating prolactin tended to decrease with time in both groups. 4. Plasma luteinising hormone (LH) concentrations increased concurrently with the decrease of prolactin. The increase was more abrupt in group B hens. 5. Plasma oestradiol concentrations decreased slightly on the day chicks were introduced. The decline was arrested by removal of chicks in group B; in group A the tendency was reversed about 10 days after chick introduction. 6. Irrespective of group, before chick removal hens which deserted their nest rapidly had less contact with chicks and lower prolactin concentrations.     

鸡传染性法氏囊病中等毒力活疫苗对H9亚型禽流感灭活疫苗体液免疫应答影响的研究

将150只维扬麻鸡商品雏鸡随机分为Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ 5组,Ⅰ、Ⅱ、Ⅲ组对应免疫A、B、C 3种IBD活疫苗和同一种H9亚型AI灭活疫苗,Ⅳ组为免疫对照组,只免疫H9亚型AI灭活疫苗,Ⅴ组为空白对照组。IBD中等毒力活疫苗二免后,定期监测鸡群H9亚型AI灭活疫苗免疫后的HI抗体消长情况,以评价这3种IBD活疫苗对H9亚型AI灭活疫苗体液免疫应答的影响。结果发现,45日龄前（即IBD疫苗二免后23 d前、H9亚型AI灭活疫苗二免后20 d前）,Ⅰ组与Ⅳ组、Ⅱ组与Ⅳ组H9亚型AIV抗体水平均差异显著（P<0.05）,Ⅲ组与Ⅳ组间差异不显著（P>0.05）。在45日龄后（即H9亚型AI灭活疫苗二免20 d后）,试验鸡的H9亚型AIV HI抗体水平均无显著差异。     

鸡新城疫（ND）各种免疫程序的测定

本试验进行了三批鸡的免疫研究。第一批试验检测不同类型新城疫疫苗在不同母源抗体水平（高和低）的鸡体上的免疫效果。结果显示,在高母源抗体时免疫,Ｖ４组和油乳剂灭活苗级抗体水平表现较低,而在低母源抗体时免疫,几种疫苗的抗体水平上升得很快,特别Ｌａｓｏｔａ－克隆３０组最明显,而油乳剂灭活苗组的抗体水平保持最长。根据此结果而制定了不同的免疫程序,进行了第二、第三批免疫试验,并分别在４５天龄及７０天龄时进行强