共查询到20条相似文献，搜索用时 296 毫秒
1.
Single and combined infections of specific-pathogen-free chickens with infectious bursal disease virus and an intestinal isolate of reovirus 总被引：2，自引：0，他引：2
The susceptibility of 1-day-old and 7-day-old specific-pathogen-free chickens to infection with a virulent strain of infectious bursal disease virus (IBDV) or an intestinal isolate of avian reovirus, or a combination of the two, was investigated. Chickens infected with IBDV and reovirus had more severe pathological lesions than chickens infected with either virus alone, and prior infection with IBDV enhanced the pathogenicity of enteric reovirus. Virus recovery was attempted from bursa, spleen, thymus, liver, intestine, pancreas, cecal tonsils, heart, and tarso-metatarsal tendons. Viruses were recovered from all tissues sampled for either IBDV or reovirus isolation, and indications were that infection with IBDV before infection with reovirus led to longer persistence of reovirus in some tissues. Antibodies to IBDV or reovirus were measured by the virus neutralization test and enzyme-linked immunosorbent assay. Chickens infected with IBDV had lower (P less than 0.05) antibody responses to reovirus than chickens infected with reovirus alone. 相似文献
2.
At 35 days of age, chickens which as 1-day-old chicks were inoculated with the infectious bursal disease virus (IBDV) had significantly lower antibody titers against Mycoplasma synoviae, Newcastle disease virus, and infectious bronchitis virus than did those never inoculated with IBDV. The IBDV also had a marked effect on the development of air-sac lesions. Birds infected with IBDV that were later inoculated with M synoviae (day 14), Newcastle disease virus (days 14 and 28) experienced an increased incidence and greater seversity of airsacculitis than did chicks which were not exposed to IBDV. 相似文献
3.
Primary and secondary immune responses to Newcastle disease virus (NDV) was evaluated in chickens infected with infectious bursal disease virus (IBDV) at one and 28 days of age. The geometric mean primary hemagglutination-inhibition antibody titers (GMT) of chickens infected with IBDV at one day of age was significantly lower (P less than or equal to 0.01) than those infected at 28 days of age. Infection with IBDV had no influence on secondary immune response to NDV. The effect of IBDV infection at one day of age on the cell-mediated immunity of chickens was evaluated by skin allograft acceptance or survival time. There was no significant difference between the percentage of grafts accepted in IBDV infected and noninfected control chickens. However, the mean graft survival time in the IBDV infected chickens was significantly longer (P less than or equal to 0.05) than those in the control group. This suggested a suppression of cell-mediated immunity due to IBDV infection. 相似文献
4.
Two commercially available live reovirus vaccines, alone or in combination with two infectious bursal disease virus (IBDV) vaccines, were evaluated for safety and efficacy in specific-pathogen-free leghorn chicks. Four trials were conducted to evaluate the vaccine combinations. At periodic intervals during the trials, tissues were collected and assayed for residual reovirus and examined for histological changes. Six weeks following reovirus vaccination, all treatment groups were challenged with a virulent field isolate of reovirus and sampled 1 week later for the final time. The two reovirus vaccines were safe and effective if given at 1 week of age, regardless of whether the vaccinates had been exposed to IBDV at 1 day. However, both reovirus vaccines persisted in the tendons of 1-day-old vaccinates. The effects of IBDV vaccines were generally minor and reflected by increases in the number of pre-challenge or post-challenge virus recoveries from some of the treatment groups receiving both type vaccines. 相似文献
5.
J J Giambrone J P Donahoe D L Dawe C S Eidson 《American journal of veterinary research》1977,38(5):581-583
Chicks which had been inoculated with infectious bursal disease virus (IBDV) at 1 day of age had a severe depression of bursa-dependent humoral immune functions by day 42. Antibody responses against rabbit red blood cells or to immunization with bovine serum albumin were significantly suppressed. In contrast, chicks inoculated with IBDV at 21 days of age produced near normal antibody responses as compared with the responses in noninfected control chicks. The IBDV had no significant effect on the thymus-dependent cellular responses as measured by skin graft rejection or delayed type hypersensitivity reactions to tuberculin. 相似文献
6.
M A Goodwin J Brown M A Smeltzer T Girshick S L Miller T G Dickson 《Avian diseases》1992,36(2):356-358
Antibody titers for infectious bursal disease virus (IBDV), infectious bronchitis virus, Newcastle disease virus, and reovirus from chicks with chicken anemia agent (CAA) antibodies were compared with antibody titers from their CAA-antibody-negative counterparts. These comparisons were made in 396 chickens that were 1 day, 2 weeks, 8-9 weeks, 10 weeks, 17 weeks, or 29-32 weeks old. Only one serum sample was collected from any given chick or chicken. There were no significant differences between the antibody titers at any age for any antigen, with one exception: at 29-32 weeks, the IBDV titers were higher (t = 2.62, df = 142, P less than 0.01) in chickens with CAA antibody. Although not at all likely, we believe that the observation of high IBDV antibody titers in CAA-antibody-positive chicks could have been a spurious one. 相似文献
7.
Biological control of Salmonella typhimurium in young chickens 总被引：3，自引：0，他引：3
A Hinton D E Corrier G E Spates J O Norman R L Ziprin R C Beier J R DeLoach 《Avian diseases》1990,34(3):626-633
The effect of dietary lactose and anaerobic cultures of cecal microflora of mature chickens on the colonization of young broiler chickens by Salmonella typhimurium was evaluated. Newly hatched chicks were given either no treatment (controls), anaerobic cecal cultures, lactose (2.5%) in the drinking water, or both anaerobic cultures and lactose. Chicks were challenged per os at 3 days of age with either 10(6) or 10(8) S. typhimurium resistant to nalidixic acid and novobiocin. On day 10, the cecal contents of the chicks were examined for S. typhimurium, pH, short-chained volatile fatty acids (VFAs), undissociated VFAs, and lactic acid. Chicks given either lactose alone or cecal anaerobes alone had significantly (P less than 0.05) fewer S. typhimurium recovered from their ceca than the controls. Chicks given the combination of dietary lactose and cecal anaerobes had significantly fewer S. typhimurium recovered from their ceca than the chicks given dietary lactose or cecal anaerobes alone. Chicks given lactose had significant (P less than 0.05) increases in the lactic acid concentration of their cecal contents. Increased lactic acid concentrations were directly correlated to decreased cecal pH values and caused a reduction in the total concentration of VFAs but a significant (P less than 0.05) increase in the undissociated form of some VFAs. 相似文献
8.
Embryo vaccination with infectious bursal disease virus alone or in combination with Marek's disease vaccine 总被引：1，自引：0，他引：1
J M Sharma 《Avian diseases》1985,29(4):1155-1169
Studies with specific-pathogen-free chickens revealed that chicks hatching from eggs inoculated at the 18th day of embryonation with infectious bursal disease (IBD) vaccine viruses of low virulence (isolates TC-IBDV and BVM-IBDV) developed antibody against IBD virus (IBDV) and resisted challenge with virulent IBDV at 3 weeks of age or older. Embryo vaccination did not adversely affect hatchability of chicks or survival of hatched chicks. Chicks embryonally vaccinated with TC-IBDV had transient histologic lesions in the bursa of Fabricius at hatch. Similar but milder lesions were also noted in chickens that received TC-IBDV at hatch. The level of protection following embryo vaccination with TC-IBDV and BVM-IBDV was similar to that following vaccination with the same vaccines at hatch. Vaccine viruses of moderate virulence (isolates BV-IBDV and 2512-IBDV) were not suitable as vaccines in embryos lacking maternal antibody to IBDV, because the vaccinated chicks developed acute IBD after hatch. Isolate 2512-IBDV was not pathogenic for embryos bearing maternal antibody to IBDV. Maternal antibody against IBDV interfered with efficacy of embryo vaccination with BVM-IBDV but not with 2512-IBDV. Embryo vaccination with a mixture of vaccines against IBD and Marek's disease resulted in protection of hatched chicks against challenge with virulent IBDV and Marek's disease virus. 相似文献
9.
以非免疫健康雏鸡为靶动物,对中药＂复方黄金颗粒＂治疗人工感染法氏囊病雏鸡进行了系列研究。结果显示：①给药试验组与未给药感染对照组相比,天冬氨酸氨基转移酶（Ast）和丙氨酸氨基转移酶（Alt）差异显著（P〈0.05）,且Ast/Alt比值极显著（P〈0.01）低于阳性对照组,显著高于阴性对照组（P〈0.05）。②血清总蛋白（TP）、白蛋白（ALB）、球蛋白（GLB）在试验结束时试验组与阴性对照组相比差异显著（P〈0.05）。③给药试验组鸡死亡率显著低于未给药感染对照组（P〈0.05）,治愈率和有效率分别为90.0%和93.3%。④对治疗7 d未死的鸡只剖检,观察法氏囊损伤与肌肉出血程度,并对其病理变化程度进行了比较：给药试验组鸡的法氏囊损伤与肌肉出血程度病理分值均显著低于未给药感染对照组（P〈0.05）;对试验鸡法氏囊进行病理组织观察,中药＂复方黄金颗粒＂可以明显降低法氏囊病毒对法氏囊的损伤。结论：以枸杞子、菟丝子等中药制成的复方黄金颗粒剂对人工感染鸡传染性法氏囊病毒病具有显著的治疗效果。 相似文献
10.
Effect of avian reoviruses on lymphoid organ weights and antibody response in chickens 总被引：1，自引：0，他引：1
Several avian reoviruses were screened to determine their effects on the immune system by inoculating them subcutaneously (SQ) into day-old chicks. For comparison, infectious bursal disease virus (IBDV) was similarly evaluated. The response of the immune system was measured functionally by the hemagglutination-inhibition (HI) response to Newcastle disease virus (NDV) and structurally by changes in the organ-to-body-weight ratios of the bursa of Fabricius, thymus, and spleen. When inoculated SQ, most of the reoviruses caused transient alterations in lymphoid organ weights, decreasing the bursa weight and increasing the spleen weight. Of those reoviruses tested, only one--a commercial vaccine based on the isolate S-1133--demonstrated the ability to interfere significantly with NDV-HI responses, although several had numerically lower titers. Two of the isolates were also evaluated by oral inoculation. Giving the viruses orally did not cause any alterations in organ weights; however, both isolates depressed the HI response of chicks to NDV. Compared with reoviruses, IBDV significantly depressed NDV-HI titers. The structural responses to IBDV differed, however: IBDV significantly depressed bursa weights for all 3 weeks of the test period without affecting spleen weights. Some of the reovirus isolates inoculated SQ were lethal for day-old chicks. This, and their ability to alter the lymphoid-to-body-weight ratios of the spleen and bursa, could be considered valid criteria by which to study the pathogenesis of these agents. 相似文献
11.
Chicks were vaccinated with an Arkansas strain of infectious bronchitis virus (IBV) vaccine when they were 1 day (Trial 1) or 4 weeks old (Trial 2). Starting at 4 weeks 3 days of age, chicks in both trials were subjected to an assay that measures the immunofunctional response of the gland of Harder (GH), one of the components of the head-associated lymphoid tissue (HALT). The assay involved multiple ocular exposures to killed Brucella abortus antigen, after which tears were collected and titered for antibodies to B. abortus. Following this, select tissues from vaccinated and unvaccinated chicks were collected and examined microscopically for specific lesions. Both functional and structural alterations were detected in the HALT of IBV-vaccinated chicks. Antibody titers to B. abortus in vaccinated chicks were significantly lower (P less than 0.05) than in unvaccinated controls. Structurally, there were elevations (P less than 0.01) in the number of lymphoid cells and follicles found in the mucosal lining of the nasal cavity. This occurred in the vaccinated chicks of both trials. Otherwise, histologic changes were confined to the chicks vaccinated at 4 weeks of age (Trial 2). In that trial, there were elevations in lymphoid-cell and follicle numbers in the eyelid (P less than 0.01) and lacrimal gland (P less than 0.05). 相似文献
12.
13.
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. 相似文献
14.
Chickens vaccinated with infectious bursal disease virus (IBDV) early in life and revaccinated with an inactivated, oil-adjuvant IBDV vaccine at 18 weeks of age produced and maintained high levels of virus-neutralizing (VN) antibody through 10 months of lay. VN-antibody titers of chicks hatched from eggs laid during the same period closely matched the average VN-antibody titers of the dams. A sequential study of the decline rates of IBDV maternal antibody (MAB) in unvaccinated and IBDV-vaccinated chicks showed that the vaccine virus did not accelerate the antibody depletion rate in vaccinated chicks. Chicks carrying high IBDV MAB showed no active immune response to vaccination with commercial IBDV vaccines. They were also refractory to a pathogenic field isolate of IBDV (FV). However, chicks with low levels of MAB responded to both vaccine virus and the FV, although their response to vaccine virus was milder and delayed. 相似文献
15.
共轭亚油酸对肉仔鸡体组成和肉品品质的影响 总被引：1，自引：3，他引：1
本试验旨在探讨日粮添加共轭亚油酸(CLA)对肉仔鸡体组成和肉品品质的影响。240只1日龄肉仔鸡随机分配到4个日粮处理组(0%、0.25%、0.5%和1%CLA),每个处理6个重复,每个重复10只鸡。试验结果表明:42d时,0.5%和1%CLA组肉仔鸡胸肌率显著高于对照组(P<0.05),1%CLA组肉仔鸡42d腿肌率显著高于对照组,肉仔鸡的腹脂率在各处理之间没有显著差异(P>0.05),1%CLA组肉仔鸡胸肌粗蛋白质粗脂肪比显著高于对照组(P<0.05)。0.5%、1%CLA组肉仔鸡胸肌滴水损失和丙二醛(MDA)含量显著降低(P<0.05)。试验结果表明,CLA可改善肉仔鸡屠体性状,增加鸡肉系水力和延长货架存放时间。 相似文献
16.
OBJECTIVE: To examine effects of virus exposure on embryonic lymphoid organ structure, apoptosis, and lymphoid cell subpopulations. ANIMALS: Eggs of specific pathogen free (SPF) White Leghorn chickens at embryonation day (ED) 17. PROCEDURES: Eggs were inoculated with 2,000 plaque-forming units (PFU) of serotype 1 herpesvirus (Marek's disease virus [MDV 1]), 2,000 PFU of herpesvirus of turkeys (MDV 3), or 1,000 embryo infectious doses (EID50) of infectious bursal disease virus (IBDV). On post-inoculation days (PID) 3 and 5, lymphoid organ to body weight ratios were determined, and bursa of Fabricius, thymus, and spleen were evaluated for lesions and apoptosis. Proportions of lymphoid cell subpopulations of PID-3 chicken embryos and 7- to 10-day-old chicks were quantitated by flow cytometry. RESULTS: Lymphoid organ weights were similar in virus-free, MDV1, and IBDV groups. Embryos inoculated with 2,000 PFU MDV 3/egg had lower bursal weights than virus-free controls. In a repeated trial, MDV 3 (1,000 PFU to 4,000 PFU) did not reduce bursal weights among groups. Histologic changes were seen in bursae after MDV 1 and IBDV inoculation. Apoptosis was greater in bursae of MDV 1-infected embryos than controls. Lymphoid cell subpopulations were similar among all groups with the exception of CD8+ and IgM+ cells in spleens of IBDV-infected 10-day-old chicks. CONCLUSIONS AND CLINICAL RELEVANCE: Infection with pathogenic strains of MDV 1 and IBDV did not alter lymphocyte subpopulations in embryos or cause complete destruction of lymphoid organs. Changes in lymphoid cell subpopulations exposed as embryos to IBDV were seen only after hatching. 相似文献
17.
F. R. Dos Anjos D. R. Ledoux G. E. Rottinghaus M. Chimonyo 《British poultry science》2015,56(4):459-469
A study was conducted to determine the efficacy of bentonite clay (BC), diatomaceous earth (DE) and turmeric powder (TUM) in alleviating the toxic effects of aflatoxin B1 (AFB1).
A total of 250 Ross-308 d-old male broiler chicks were assigned to 10 dietary treatments (5 replicates of 5 chicks) from hatch to d 21. Dietary treatments were: basal diet; basal diet plus AFB1 (2 mg) or BC (0.75%), or DE (0.75%), or TUM (200 mg/kg curcuminoids) and different combinations of AFB1, BC, DE and TUM.
Feed intake (FI), body weight gain (BWG) and feed gain (FG) of the birds fed on BC or DE separately were not different from control birds. Birds fed on TUM only had similar FI and FG but lower BWG than control chicks.
Aflatoxin B1 reduced FI, BWG and serum concentrations of glucose, albumin, total protein calcium, but increased FG and relative liver and kidney weights. Chicks fed on the combination of AFB1 and BC had similar FI and FG to control chicks. Chicks fed on the combination of DE and AFB1 had lower FI (23.1%) and BWG (28.6%) compared with control chicks.
Chicks fed on the combination of TUM and AFB1 also had decreased FI (26.2 %) and BWG (31%) compared with control chicks. Chicks fed on the combination of AFB1, BC and TUM consumed significantly higher amounts of feed compared with chicks fed on only AF, but gained less when compared with control diet chicks.
Chicks fed on the combination of AFB1, DE and TUM diet had poorer growth performance than those fed on AFB1 alone. None of the combination diets reduced the severity of liver lesions.
18.
《The Journal of Applied Poultry Research》2007,16(2):187-191
Reoviruses are an important cause of suboptimum performance in commercial broilers worldwide. Integrators use the enzyme-linked immunosorbent assay against the S1133 antigen for monitoring serum of breeders for indicating pullet vaccine success. However, without correlating serology to reovirus challenge, it is difficult to determine whether titers reflect protective immunity. We developed a broiler challenge test against 2 common reovirus isolates (2408 and S1133) to evaluate the efficacy of reovirus pullet vaccine programs. Two reovirus serologic and challenge studies were undertaken using chicks from broiler integrators from the southeastern United States. Breeder flocks, from which the chicks were obtained, received at least 1 live and 2 inactivated reovirus vaccines during their pullet phase. One-day-old progeny were collected from 6 breeder flocks. At 1 d of age, 20 chicks from each broiler flock were bled, and serum was analyzed for antibodies. At 3 to 4 d of age, 20 progeny per flock were challenged with the 2408 reovirus by intratracheal route. At 10 to 14 d of age, another 20 birds per flock were challenged with the S1133 reovirus by footpad. Twenty birds per flock were used as nonchallenged controls. At 3 wk of age, all birds were killed and weighed. Percentage of protection was calculated for each flock based on the absence of gross lesions. Flocks with at least 50% protection were considered well protected. Most flocks were well protected against both viruses. The percentage of protection correlated with day-old enzyme-linked immunosorbent assay titers. Chicks from younger hens had higher titers and the best protection against challenge. Producers, whose hen flocks were monitored herein, were doing a good job of immunizing pullets against reovirus. They are now using reovirus progeny challenge studies along with breeder antibody titers to determine vaccination success of their pullets. 相似文献
19.
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. 相似文献
20.
Specific-pathogen-free (SPF) chickens were inoculated with several different concentrations of chicken anemia agent (CAA) by the intra-abdominal, intratracheal, or oral routes. Based on lowered hematocrit values, the birds were most susceptible to CAA introduced by the intra-abdominal route. When SPF chickens were infected with infectious bursal disease virus (IBDV) at 1 day of age, they remained susceptible to CAA up to at least 21 days, whereas birds inoculated with CAA alone were susceptible only at 1 day of age. Infectious bursal disease virus introduced at 1 day of age also increased the susceptibility of birds to contact infection with CAA and resulted in increased mortality rates in CAA inoculates. The response of SPF birds to CAA infection varied following exposure at 1 day of age to two different strains of IBDV (STC and Variant-E). Chicken anemia agent contacts and inoculates infected with the Variant-E strain were affected 1 week earlier by CAA than by STC inoculates, as evidenced by depressed hematocrits. However, the total number of birds affected was similar for both the Variant-E and STC-inoculated chickens. Commercial broiler chickens inoculated at 1, 7, 10, and 14 days of age by non-parenteral routes with CAA or a combination of CAA and IBDV had mean hematocrits that were lower than controls. Several CAA-inoculated birds were considered anemic, with hematocrit values of 25 or less, while uninoculated birds remained within normal ranges. 相似文献