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1.
One hundred ninety-six male and female turkeys representing two genetic lines were experimentally infected with Bordetella avium. The lines of turkeys included a randombred control line (RBC2) and a subline (F) of RBC2 selected for increased 16-wk body weight. No difference was found between lines RBC2 and F in the number of days to onset of clinical signs, and no mortality due to B. avium infection was observed in either line. Interestingly, however, a significant depression (12%) occurred in body weight of F line poults infected with B. avium, but no significant depression occurred in body weight of RBC2 poults. 相似文献
2.
Seven hundred eighty male and female turkeys representing four genetic lines were challenged in four experiments with the Texas GB strain of Newcastle disease virus (NDV). The lines of turkeys included two randombred control lines (RBC1 and RBC2), a subline (E) of RBC1 selected for increased egg production, and a subline (F) of RBC2 selected for increased 16-week body weight. Mortality in turkeys of subline F (32.5%) was significantly higher than that in turkeys of line RBC2 (15.8%), subline E (17.5%), and line RBC1 (18.4%). At the end of each experiment, surviving birds were tested for antibody to NDV using the enzyme-linked immunosorbent assay (ELISA) and hemagglutination-inhibition (HI) test. Turkeys of subline E and line RBC1 had significantly lower ELISA antibody titers than those of subline F and line RBC2. Subline F had the highest HI antibody titers, followed in decreasing order by lines RBC2 and RBC1 and subline E. No apparent correlation was found between antibody response and mortality after NDV challenge. 相似文献
3.
ObianujuNkiruka Okoroafor Paul Chekwube Eze Wilfred Sunday Ezema Chika Nwosu Christian Okorie-Kanu P. C. Animoke Boniface Anene John Osita Arinze Okoye 《Tropical animal health and production》2018,50(2):345-351
The aim of this project is to study the clinical signs and lesion of velogenic Newcastle disease (vND) in commercial turkeys, and also to find out if La Sota vaccination offered protection against these signs and lesions. The cockerels were included as positive controls. One hundred and twenty turkey poults and cockerels were divided into eight groups as follows: unvaccinated unchallenged turkeys (UUT), unvaccinated challenged turkeys (UCT), vaccinated unchallenged turkeys (VUT), vaccinated challenged turkeys (VCT), and along the same lines, the cockerel groups were UUC, UCC, VUC and vaccinated challenged cockerels (VCC). Vaccination was at 3 weeks of age while challenge was at 6 weeks of age. The unvaccinated turkeys and cockerels (UCT and UCC) showed different degrees of depression, diarrhoea and later paralysis at challenge. Total mortality was 100% in cockerels within 6 days, but 60% in turkeys. Similar but milder clinical signs were found in the VCC with a total mortality of 13.3%. The VCT showed mild drop in feed and water consumption, and no mortality. All the challenged groups had significant (p < 0.05) loss of weight when compared with their controls. Necropsy showed that while the UCC had severe proventricular haemorrhages, intestinal and caecal tonsil ulcers, the UCT had no digestive tract lesion. There was severe atrophy of the lymphoid organs in all the challenged groups. Histopathological sections of the bursa, spleen and thymus in all the challenged groups with special emphasis on the vaccinated and unvaccinated turkeys with mortalities of 0 and 60%, respectively, had very severe necrosis and depletion of the lymphoid tissue. Virus was isolated from the cloacal swabs. The haemagglutination inhibition antibodies were significantly higher (p < 0.05) in the challenged groups than the unchallenged. The above observations in the intestinal tracts of UCT are of diagnostic significance while the gross and microscopic lesions in the UCT and VCT show that La Sota vaccination may not protect turkeys against the destruction of the lymphoid organs by vND as earlier reported in chickens. This may lead to immunosuppression and production problems in areas where vND is enzootic. 相似文献
4.
Candidate male and female breeders from nine genetic lines of turkeys that were reared intermingled, with the sexes housed in different buildings on the same farm, were vaccinated with a live Newcastle disease virus vaccine (B1 type, LaSota) just prior to the commencement of egg production. In 1999, an average mortality for all lines of 5.8% occurred during the 10 days immediately following vaccination and the level of mortality varied among lines. Mortality was, in general, greater in large-bodied lines than in small-bodied lines. Affected birds exhibited gross multiple areas of focal necrosis in the liver and spleen and congestion of the heart and lungs. The percentage mortality occurring following similar vaccination in 2000 averaged 2.6 for the 10 days following vaccination and mortality was greater (P < or = 0.05) in one line (F line) than the other genetic groups and higher in females than in males. Mortality in the F line, selected for increased body weight and known to be susceptible to various diseases, averaged 15.1% for both years. Attempts failed in both years to isolate Pasteurella multocida or other bacteria. There was a positive correlation between increased body weight and increased mortality following vaccination with the live LaSota vaccine. 相似文献
5.
Twelve large white turkey hens were immunized with a commercially available Bordetella avium bacterin. Hens and eggs were tested using an enzyme-linked immunosorbent assay (ELISA) to determine the response to the bacterin. Three hundred poults were then obtained from two commercial flocks, the hens of one flock having been immunized with the same bacterin used on the group of 12 turkeys. Titers of the poults were monitored for 7 weeks, and poults were challenged by exposure to infected poults at 1, 7, 14, and 21 days post-hatch. Hens produced an antibody response following immunization, with a parallel antibody response being detected in eggs. Maternal antibodies were present in poults from immunized hens. Poult titers declined to near the level of poults from unimmunized hens by 14 days of age. Poults from immunized hens challenged at 1 and 7 days were resistant to development of clinical disease and gross lesions, whereas all poults from unimmunized hens exhibited clinical signs and gross lesions. After 14 days, the resistance of both groups to development of clinical disease, became near equal, neither group being affected as severely as the unimmunized hens challenged at days 1 and 7. Six commercial turkey breeding flocks and their progeny that had not been vaccinated for B. avium and had no history of B. avium infection were evaluated with the B. avium ELISA. There were variations between the flocks, with poult titers reflecting those found in the hens. 相似文献
6.
In this study we compared protection by DNA vaccination with the F (pCMV-F) or N (pCMV-N) gene from avian metapneumovirus (aMPV) in turkeys. One-week-old turkey poults received two intramuscular injections 2 wk apart. Birds were challenged with a turkey-embryo-adapted aMPV at 5 wk of age. Birds vaccinated with pCMV-F had decreased clinical signs of disease as well as significantly reduced virus load in tracheal swabs compared with birds vaccinated with pCMV-N or unvaccinated control birds. Serum neutralizing antibodies were significantly higher in birds receiving pCMV-F compared with all other groups. These results indicate that DNA vaccination with the F, but not N, gene of aMPV can induce significant protection against aMPV infection. 相似文献
7.
We designed this study to compare the replication potential of turkey coronavirus (TCV) and its effect in chickens and turkeys and to study the effect of singleand combined infection of turkey poults with TCV and astrovirus. We studied the pathogenicity of TCV in experimentally inoculated turkey poults and chickens by observing the dinical signs and gross lesions. Two trials were conducted with 1-day-old and 4-wk-old specific-pathogen-free turkey poults and chickens. One-day-old turkey poults developed diarrhea at 48 hr postinoculation. Poults euthanatized at 3, 5, and 7 days postinoculation had flaccid, pale, and thin-walled intestines with watery contents. The 4-wk-old turkeys had no clinical signs or gross lesions. One-day-old and 4-wk-old chicks developed no clinical signs or gross lesions although the TCV was detected in gut contents of the birds throughout the experimental period (14 days). In another experiment, mean plasma D-xylose concentrations in 3-day-old turkey poults inoculated with TCV, turkey astrovirus, or a combination of both viruses were significantly lower than in the uninoculated controls. 相似文献
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9.
Four laboratory experiments were designed to study the efficacy of the only available commercial vaccine for turkey coryza, Art-Vax. Poults were vaccinated either once or twice at different ages and challenged with pathogenic Alcaligenes faecalis. In another study, commercial turkeys vaccinated at 1 and 12 days of age on a commercial farm were brought to the laboratory for challenge with pathogenic A. faecalis. Both the laboratory- and field-vaccinated poults were given the manufacturer's recommended dosage of the vaccine strain. Regardless of the vaccine schedule or source of poults, the vaccine was not effective in protecting challenged turkeys from infection. Furthermore, the vaccine was not effective in protecting poults less than 3 weeks of age from disease, but it was effective in protecting poults more than 3 weeks of age from disease. These results indicate that although vaccinated turkeys older than 3 weeks of age were not susceptible to disease, they were susceptible to infection and could act as carriers of field strains of A. faecalis, thus perpetuating the risk of infection to flocks subsequently raised in the same buildings. 相似文献
10.
The pathogenesis of hemorrhagic enteritis in turkey poults infected with hemorrhagic enteritis virus (HEV) at 3 days or at 2 or 5 weeks of age was compared with pathogenesis in poults that had been chemically bursectomized neonatally and exposed to cell-culture-propagated virus at 2 or 5 weeks of age. Conventional poults exposed to HEV at 2 or 5 weeks developed clinical disease, and mortality ranged from 38% to 100%. In addition to the splenic and intestinal lesions usually seen with HEV infection, the pancreas, bursa of Fabricius, and thymus were also affected. In contrast, although they were free from detectable maternal antibody, poults infected with HEV at 3 days of age failed to develop clinical disease or mortality; however, virus was demonstrated by histological and electron microscopic examinations in spleens of these poults. Neonatal chemical bursectomy completely prevented the clinical signs, gross lesions, and mortality induced by HEV in poults at 2 or 5 weeks of age. These findings strongly suggest that an intact bursa is necessary for HEV to induce disease in turkeys. 相似文献
11.
The interaction of a poult enteritis and mortality syndrome (PEMS)-turkey astrovirus-Ohio State University (TAst-OSU) with the mononuclear phagocytic system cells, namely macrophages, was examined after in vitro and in vivo exposure. In vitro exposures were performed by incubating adherent turkey macrophages with various volumes of 10(6) 50% embryo infective dose (EID50)/ml TAst-OSU stock, whereas for in vivo challenge, poults were given a 200 microl inoculum of 10(6) EID50/ml TAst-OSU stock at 7 days of age. Results show that TAst-OSU in vitro exposure reduced macrophage viability relative to controls (P < 0.05) and decreased phagocytosis (P < 0.05) and intracytoplasmic killing of Escherichia coli (P < 0.05) after a 42-48-hr exposure. Poults challenged with TAst-OSU in vivo recruited almost 50% fewer Sephadex-elicited inflammatory cells in the abdominal cavity (P < 0.05) as compared with the sham controls. Similar to in vitro exposure, macrophages isolated from in vivo TAst-OSU-challenged poults exhibited reduced percentage of phagocytic macrophages (P < 0.05) as well as fewer intracytoplasmic E. coli per phagocytic macrophage (P < 0.05). TAst-OSU-challenged poults had a greater number of viable E. coli in their spleens (P < 0.05) after an intravenous E. coli challenge as compared with the non-TAst-OSU-challenged control poults. Macrophage-mediated cytokines and metabolites were also examined during this study. Both in vitro and in vivo TAst-OSU challenge resulted in reduced interleukin (IL)-1 and IL-6 activity. On the contrary, nitrite levels in macrophage culture supernatant fraction of TAst-OSU-challenged macrophages were significantly higher (P < or = 0.05). The findings of these studies indicated that TAst-OSU challenge induced defects in macrophage effector functions, implying that PEMS-turkey astrovirus can potentially impair the immune response of turkeys, thereby leading to enhanced susceptibility of turkeys to secondary, perhaps even fatal, bacterial infections. 相似文献
12.
Hemorrhagic enteritis of turkeys: influence of maternal antibody and age at exposure 总被引：1，自引：0，他引：1
The effect of maternal antibody (MAB) to hemorrhagic enteritis (HE) on the response of turkeys to infection with virulent and avirulent strains of HE virus (HEV) was examined. The influence of age at exposure and treatment with HEV antibody on development of clinical HE also was studied. MAB protected poults from clinical HE for up to 6 weeks of age. MAB also interfered with vaccination against the disease for at least 5 weeks after hatching, as indicated by absence of HEV antigen in spleens and by poor seroconversion at 6 days and at 3 weeks post-vaccination, respectively. The incidence of clinical HE in MAB-negative poults was significantly higher in poults inoculated with virus at 15 days of age or older than in poults inoculated at 1-13 days of age. Further, MAB-negative poults embryonally inoculated with virulent or avirulent strains of HEV did not develop disease; these poults developed antibody and resisted challenge with virulent virus at 6 weeks of age. Poults treated with HE antibody within 1 hour of challenge or at 1, 3, or 5 weeks before challenge with virulent virus were protected against lesions and mortality induced by HEV. These results suggest that MAB may influence susceptibility of turkeys to infection with HEV for at least 5 to 6 weeks after hatching, unlike the case with most other viral infections of poultry. The results confirm that early age resistance to clinical HE is independent of MAB and suggest that such resistance persists for up to 13 days of age. The data also suggest that turkeys lacking MAB can be immunized against HE by embryo vaccination. 相似文献
13.
Intestinal and bursal cryptosporidiosis in turkeys following inoculation with Cryptosporidium sp. isolated from commercial poults 总被引：1，自引：0，他引：1
Cryptosporidium meleagridis oocysts, originally isolated from droppings of commercial turkey poults with increased mortality due to viral (reovirus) hepatitis and enteritis, were treated with peracetic acid to kill companion bacteria and viruses and then propagated by passage in young turkeys. Thirty-eight 5-day-old large white turkey poults were inoculated by crop gavage with 500,000 cryptosporidial oocysts and compared with 40 uninoculated poults. Cryptosporidial oocysts shedding began 3 days postinoculation (PI), peaked on day 4 PI, and persisted at a low level for the duration of the 21-day trial. Low to moderate cryptosporidial infections of the ileal mucosa (days 3, 6, and 15 PI), cecal mucosa (days 3, 6, and 21 PI), and bursa of Fabricius (days 6, 12, 15 and 21 PI) were found on histopathological examination. There were no differences in mean body weights between the inoculated and uninoculated groups, and no mortality or clinical signs of disease were seen in either group. 相似文献
14.
Two-week-old straight-run white broiler chicks and 2-week-old straight-run white turkey poults were fed seed or whole plants Cymopterus watsonii or seed of Cymopterus longipes at 0.4, 0.8, and 1.6% of body weight, and then placed in sunlight for 5 hours each day for 7 days. All plant material produced moderate to severe photosensitivity in chicks. Toxic signs included photophobia; red discoloration of beak, comb, and feet; loss of feathers in the periorbital area; dried serous fluid on comb and edge of beak; keratoconjunctivitis; and multiple lesions on feet and legs. Turkey poults showed a syndrome similar to that of chicks. Mortality was particularly high in turkeys fed C. longipes seed. Toxic signs in turkeys 6 weeks after treatment included tremors in the legs; upturning and shortening of the upper beak; and shortening disfigurement, and gangrene of the toes. Two phototoxic furocoumarins, oxypeucedanin and isoimperitorin, were isolated from C. longipes seed. Either compound, administered orally, produced photosensitivity in 2-week-old chicks. 相似文献
15.
The osmotic fragility of red blood cells (RBC) from Eimeria adenoeides-infected turkey poults was compared with that of RBC from control and water-deprived poults. At different hypotonic NaCl concentrations, lysis of RBC from infected poults was 10 to 35% less on day 4 postinoculation (PI) and 50 to 65% less on day 7 PI than that of controls. Red blood cells of poults deprived of water for 3 days were also resistant to lysis; the percent lysis was roughly the same as that of RBC from infected poults at day 7 PI. Incubating control RBC in plasma from infected poults, in extracts of infected ceca, or at different pH levels did not increase their resistance to lysis, suggesting that neither a stabilizing factor in the plasma that had rapid effect on the RBC nor a transient shift in blood pH was involved. Mean RBC size differed little among infected, water-deprived, and control poults (14.0-14.2 X 8.0-8.1 X 3.8 microns). However, although 3.5% of RBC population of control and water-deprived poults were immature (mid to late polychromatic erythrocytes), only 0.4% of the RBC of infected poults were immature. The data suggest that reduced water intake as well as other factors may be involved in the decreased osmotic fragility of RBC from poults infected with E. adenoeides. 相似文献
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17.
Antibiotic aerosolization: the effect on experimentally induced Alcaligenes rhinotracheitis in turkeys 总被引：1，自引：0，他引：1
Oxytetracycline hydrochloride was delivered by aerosol twice daily for 3 days to uninfected turkeys and to turkeys experimentally inoculated with Alcaligenes faecalis. The clinical, microbiological, and histological changes in the upper respiratory tracts were studied. No lesions were observed in the tracheas of uninoculated poults exposed to the aerosol. In experimentally infected poults, clinical signs included ocular and nasal discharges and open-mouthed breathing. Histologic lesions included progressive bacterial colonization of ciliated epithelium, loss of cilia, depletion of mucin from goblet cells, and accumulation of inflammatory cells within the tracheal lumen. Aerosolization of oxytetracycline effected a temporary decrease in bacterial colonization and a delay in clinical signs and histologic lesions in infected treated poults compared with untreated infected poults. Bacterial colonization and histologic lesions in the tracheas of both treated and untreated infected poults were similar by 4 days after the treatment was discontinued. This study indicates additional research with bactericidal antibiotics is needed to further evaluate antibiotic aerosolization as a treatment for alcaligenes rhinotracheitis. 相似文献
18.
Field studies with convalescent serum and infectious bursal disease vaccine to control turkey coryza
Convalescent serum given to 1-day-old poults delayed clinical signs of turkey coryza by several days and reduced mortality on infected farms. Turkey breeders immunized with cell-culture-adapted infectious bursal disease virus (IBDV) or turkey infectious bursal disease virus (TIBDV) had a marked increase in virus-neutralization (VN) antibody titers. The VN antibody titer was significantly higher in progeny poults than in poults from unimmunized breeders. Clinical turkey coryza and mortality was considerably less in poults from IBD- or TIBD-vaccinated breeders than in control poults. They also responded more favorably to hemorrhagic enteritis and fowl cholera vaccination. 相似文献
19.
《The Journal of Applied Poultry Research》2014,23(3):478-485
The objective of this work was to develop and evaluate the immunomodular effect of a DNA vaccine based on the fusion (F) gene of avian metapneumoviruses (aMPV) and to study its protection against field virus challenge, as this will help to better control the disease in turkeys. In this study, the F protein of the Egyptian isolate (Giza-turkey rhinotracheitis-4) of the B-subtype of aMPV isolated in 2009 was expressed from a DNA plasmid in Vero cells. After 1 i.m. injection of turkey poults with this plasmid, the antibody response was detected by ELISA. The turkey poults inoculated with locally prepared DNA aMPV vaccine had highly significant phagocytic activity, as measured by phagocytic percent and index of macrophage activation, in comparison to those inoculated with inactivated and live attenuated vaccines and with the noninfected control group. Intratracheal challenge of turkey poults at 21 d postvaccination by a dose of 100 uL of field Egyptian Giza-turkey rhinotracheitis-4 virus of a titer 6 log10 tissue culture infective dose 50 resulted in 100% protection in poults that received locally prepared DNA aMPV vaccine, whereas those that received commercial aMPV vaccines experienced 80 and 90% protection; typical clinical signs of aMPV infection were seen in control nonvaccinated poults. Therefore, a high success rate was noted when using F gene DNA plasmid vaccine by the induction of a potent immunomodular effect for both cell-mediated and humoral immune response. The use of the F gene DNA plasmid vaccine developed in this study provided 100% protection in vaccinated poults, which can help in controlling aMPV infections in turkeys. 相似文献
20.
Alcaligenes faecalis rhinotracheitis in Manitoba turkeys 总被引：1，自引：0，他引：1
An outbreak of alcaligenes rhinotracheitis occurred on one premises housing five turkey flocks totaling 25,000 poults. Prominent findings were severe respiratory difficulty resulting from excess mucus in the nasopharynx, lachrimation, and tracheal collapse. Sinus and tracheal cultures consistently yielded Alcaligenes faecalis. An adenovirus was isolated and four flocks became positive for CELO virus by agar-gel-precipitin (AGP) tests. Mortality by flocks ranged from 4% to 48%. Treatment was unsuccessful and appeared to increase the mortality rate. The course of the disease was about 6 weeks, and recovered turkeys were marketed 1 week later than the usual date. 相似文献