Showing papers in "Avian Diseases in 1970"
TL;DR: HVT gives substantial protection against the development of MD yet is nonpathogenic and noncontagious, all of which are important characteristics of vaccine viruses.
Abstract: SUMMARY Studies were conducted to determine whether a herpesvirus isolated from turkeys (HVT) would protect chickens against subsequent challenge with the virulent JM strain of Marek's disease herpesvirus (MDHV). HVT administered intra-abdominally at doses as low as 600 plaque-forming units per one-day-old chick gave protection against Marek's disease (MD). The virus would protect when birds were challenged with MDHV by intra-abdominal inoculation at 3 weeks or by contact exposure as early as 2 weeks postvaccination. Chickens inoculated with HVT and observed for 17 to 20 weeks did not develop lesions. Birds produced antibody and infection persisted throughout this period, however, as indicated by reisolation of the virus. Furthermore, HVT did not spread to chickens in direct contact with vaccinated birds. Thus HVT gives substantial protection against the development of MD yet is nonpathogenic and noncontagious, all of which are important characteristics of vaccine viruses.
413Â citations
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182Â citations
TL;DR: The adequate serological studies can disclose how closely related the viruses are and whether there is a speculative possibility that the IBV strains which are ubiquitous in almost all poultry populations can serve as reservoirs for human common cold infections, e.g. through mutation of IBV or hybridization of animal and human coronaviruses.
Abstract: In the last few years, strains have been isolated from various human common cold epidemics which resemble avian infectious bronchitis virus (IBV) so much, both morphologically and in other properties, that they have been called IBV-like viruses. It has also been found that the mouse hepatitis virus is morphologically identical with them. All these viruses seem to constitute a group of their own and are known to possess at least the following common properties: 1) size 80-160 m/; 2) characteristic surface structure; 3) sensitivity to lipid solvents; 4) ribonucleic acid content; 5) low density of infectious units (1.18-1.19 in sucrose gradient); 6) development in the cytoplasma by budding into cisternae or vesicles. The nucleocapsid structure of these viruses is still unknown. Because of the characteristic appearance, recalling the solar corona, the name coronaviruses has been suggested. Besides avian infectious bronchitis virus and mouse hepatitis virus, this virus group at present includes five IBV-like human strains: B814, 229E, OC43, LP, and EVS. Some comparisons in cross-neutralization tests have been made among the viruses of the group. The results showed that they all seem to belong to distinct serotypes. However, it was necessary to use several neutralization methods since no common method applicable to all the strains was available. Hence, conclusions based on those results must be treated with reserve. First, the adequate serological studies can disclose how closely related the viruses are and whether there is a speculative possibility that the IBV strains which are ubiquitous in almost all poultry populations can serve as reservoirs for human common cold infections, e.g. through mutation of IBV or hybridization of animal and human coronaviruses.
94Â citations
TL;DR: Aflatoxin consumed immediately before the immunizing period did not impair the development of a solid immune response and mean agglutinin titers of the vaccinated aflatoxin recipients were of the same magnitude as those of vaccinated recipients of normal rations.
Abstract: Aflatoxin (0.25-0.5 ppm B1 activity) consumed during or after the period of immunization against Pasteurella multocida interfered with the development or manifestation of acquired resistance in 2067% of turkey poults and chicks. Aflatoxin consumed immediately before the immunizing period did not impair the development of a solid immune response. Aflatoxin fed for 3 weeks caused changes in several parameters including reduced rate of gain in body weight, histologic changes of the liver, and reduced levels of several plasma proteins. When an aflatoxin-free ration was fed for 3 weeks after toxin consumption, each of the above parameters returned to normal, but the defect in immunity remained when the principals had been immunized during the period of aflatoxin consumption. Plasma protein changes included reduced levels of total protein, a,p-globulin, and albumin; levels of a-globulin remained normal. Mean agglutinin titers of the vaccinated aflatoxin recipients were of the same magnitude as those of vaccinated recipients of normal rations.
80Â citations
TL;DR: Preliminary studies with Salmonella infantis and S. typhimurium showed that those salmonellae do not persist as long in built-up poultry litter as in fresh litter, and the shed rate of birds on built- up litter suggests an inhibitory effect for salmonella in the litter.
Abstract: SUMMARY Preliminary studies with Salmonella infantis and S. typhimurium showed that those salmonellae do not persist as long in built-up poultry litter as in fresh litter. The shed rate of birds on built-up litter suggests an inhibitory effect for salmonellae in the litter. This effect may reduce salmonellae in either the litter or the intestinal tract. Cycling of salmonellae between litter and the intestinal tract appears of significance in maintaining intestinal infection. This cycling is more evident in unchanged new litter than in built-up litter or in fresh litter changed periodically. Fresh litter replaced periodically did not appear to differ from built-up litter in infection rate. Contamination levels of the two litters were similar.
57Â citations
TL;DR: Test procedures were developed that make possible the use of HA-elution patterns from chicken erythrocytes for differentiation of NDV strains, and it is feasible to use rate of elution as a genetic marker as well as a character for identifyingNDV strains.
Abstract: Test procedures were developed that make possible the use of HA-elution patterns from chicken erythrocytes for differentiation of NDV strains. The 53 strains and 16 clones examined were separated into 2 distinct groups of rapid and slow eluters. Both slow and rapid eluters were represented equally in the 3 NDV pathotypes (velogenic, mesogenic, and lentogenic). No relationship was found between HA-elution patterns and other properties of the same strain. It is feasible to use rate of elution as a genetic marker as well as a character for identifying NDV strains.
54Â citations
54Â citations
TL;DR: The incidence of hematopoietic destructive lesions was reduced when genetically similar chicks from artificially immunized antibody-positive dams were inoculated with acute MD agent and an absence of antibody to MD-associated herpesvirus was revealed.
Abstract: Hematopoietic destructive lesions, characterized by necrosis and loss of architecture in the bursa of Fabricius and thymus, were observed consistently in second-generation specific-pathogen-free X Line 7 (SPF X L7-F2) cross chickens inoculated at 1 day with an acute form of Marek's disease (MD) agent. In addition, there was a drastic reduction in packed cell volume and lack of hematopoiesis. Serologic examination of the dams of these chicks revealed an absence of antibody to MD-associated herpesvirus. The incidence of hematopoietic destructive lesions was reduced when genetically similar chicks from artificially immunized antibody-positive dams were inoculated with acute MD agent. The unusual response in chicks inoculated with acute MD is thought to be explainable on the basis of varying degrees of passive protection through maternal antibody. Chicks without such protection are more prone to develop aplasia of bone marrow and necrosis of bursal and thymic lymphoid elements.
54Â citations
TL;DR: Parameters of naturally occurring Marek's disease herpesvirus (MDHV) infection in commercial broilers were studied in 2 trials, each involving paired flocks, suggesting that this was the most probable source of flock infection.
Abstract: SUMMARY Parameters of naturally occurring Marek's disease herpesvirus (MDHV) infection in commercial broilers were studied in 2 trials, each involving paired flocks. MD condemnations ranged from 6.0 to 15.3%, though little difference was noted between flock pairs, and the pattern of infection in all 4 flocks was similar. Chicks were apparently free of infection at hatching, despite their origin from infected breeder flocks. MDHV could be demonstrated indirectly as early as 9 or 16 days of age in 2 of the flocks. Infection was detected directly at 4 weeks by the presence of microscopic lesions and the isolation of MDHV. Acquired antibody appeared at 6 to 7 weeks. At processing (8 weeks), MDHV was isolated from 98 of 99 birds tested from all flocks and 78%1 had microscopic lesions. Virus infection appeared related directly to lesion response, though the relationship of these parameters to MD condemnations could not be determined. MDHV was demonstrated in samples of litter and dust from 1 of 4 houses prior to the introduction of chicks, suggesting that this was the most probable source of flock infection.
51Â citations
TL;DR: Field experience with Marek's disease suggests that physiochemical and/or biological environmental factor(s) might affect the development and clinico-pathological manifestations of MD.
Abstract: Field experience with Marek's disease (MD) suggests that physiochemical and/or biological environmental factor(s) might affect the development and clinico-pathological manifestations of MD. Little is known of their role, although investigation of factors which may contribute to the severity of this disease could be of considerable significance for control of MD in the field. Proudfoot and Aitken (14) reported a significantly higher mortality from MD in chickens raised on a higher protein diet. Katzen et al. (10) noted some remission of MD symptoms when
TL;DR: Convalescent levels of influenza antibodies were demonstrated by an agar gel precipitin (AGP) test in turkey sera after field outbreaks, facilitating a diagnosis of avian influenza using a suspect virus or paired sera without the influences of strain-to-strain antigenic differences, which limit the usefulness of the hemagglutination-inhibition test.
Abstract: Convalescent levels of influenza antibodies were demonstrated by an agar gel precipitin (AGP) test in turkey sera after field outbreaks. The AGP test was positive with chicken sera for at least 8 weeks after laboratory exposure to any of 3 influenza strains, and positive with turkey sera for at least 12 weeks after exposure. The AGP test facilitates a diagnosis of avian influenza using a suspect virus or paired sera without the influences of strain-to-strain antigenic differences, which limit the usefulness of the hemagglutination-inhibition test.
TL;DR: A study of the persistence of MD virus in big broiler houses where the MD agent VUB-X (Veterinary University Brno) was isolated and the infectivity of dust collected from the ventilation system was examined.
Abstract: Acute Marek's disease (MD) is a highly contagious disease of the young chicken. The etiological agent is easily transmitted from infected to susceptible chickens by direct or indirect contact (1). It has been demonstrated in oral washings (4,5), air (7), and feces (8) of infected chickens and their environment. Witter et al. (9) suggested that the MD agent may survive for a substantial period outside the host body, a suggestion supported by the presence of the MD agent after complete depopulation. Those workers demonstrated MD agent in litter and droppings from infected chickens. Eidson et al. (3) demonstrated MD agent in adults and larvae of Alphitobius diaperinus recovered from litter contaminated by chickens with MD. It is probable that other sources, not yet identified, may exist in the environment. This paper reports a study of the persistence of MD virus in big broiler houses where the MD agent VUB-X (Veterinary University Brno) was isolated (Jurajda, unpublished data). The infectivity of dust collected from the ventilation system was examined.
TL;DR: Emulsified water-in-oil fowl cholera bacterins prepared from 3 strains of formalin-killed Pasteurella multocida induced a high degree of immunity in turkeys against homologous but not heterologous challenge, demonstrating at least 3 immunogenic types of P.Multocida associated with fowl Cholera.
Abstract: SUMMARY Emulsified water-in-oil fowl cholera bacterins prepared from 3 strains of formalin-killed Pasteurella multocida induced a high degree of immunity in turkeys against homologous but not heterologous challenge, demonstrating at least 3 immunogenic types of P. multocida associated with fowl cholera. However, both vaccinated and unvaccinated turkeys that survived challenge exposure were immune when re-exposed to different immunogenic strains, demonstrating an immune response to live P. multocida different from that to killed. A one-ml dose of bivalent bacterin was more effective than a 0.5-ml dose in protecting turkeys against experimentally induced fowl cholera. In a comparison of exposure methods, the commonly used method of swabbing nasal clefts of turkeys with a culture of P. multocida was a more severe challenge of immunity than contact exposure challenge with infected birds. In using a challenge culture of low virulence, the intramuscular (IM) route of inoculation was better than either of the other two methods for challenging the immunity of turkeys.
TL;DR: No evidence indicated that the cecum plays an essential role in establishing or maintaining intestinal infection with S. typhimurium in chickens that had been ligated or surgically removed.
Abstract: Surgically altered and normal chickens were inoculated orally with Salmonella typhimurium and, in some instances, ferric oxide, and intestinal infection was monitored by sampling feces and cecal contents. Salmonellae initially appeared in feces in 1.5 to 22 hours, and ferric oxide in 3 to 5 hours. The organisms could not be isolated from the ceca until 24 hours. Birds whose ceca had been ligated or surgically removed had a higher shed rate than the controls. No evidence indicated that the cecum plays an essential role in establishing or maintaining intestinal infection with S. typhimurium.
TL;DR: The fluorescent antibodies appear to offer possibilities for the differentiation of IBV isolates, when diagnosing IBV or any other disease in chicken tissue one should be aware of the possibility of extraneous antibodies or antigens even in chickens which appear healthy and are from a specific pathogenfree flock.
Abstract: A wide range of cross-reactions among strains was found when immunofluorescence was used as a method for differentiation of IBV strains. Only conjugates prepared against 97 and Massachusetts strains were able to detect all the strains of IBV included in this study. The fluorescence with heterologous strains was weaker than the one present when tested with homologous strains. When the rinsing period after staining was extended from 10 minutes to 2 hours, the cross-reactions were markedly diminished, and only 97 and Holte conjugates gave bright fluorescence with other than their homologous strains. Holte conjugate gave good fluorescence with virus 97, and the 97 and 609 conjugates with Gray virus. Thus, the fluorescent antibodies appear to offer possibilities for the differentiation of IBV isolates. When infected hens were examined, IBV antigen was detected by fluorescent antibodies only in the larynx, trachea, and lung. The conjugates contained antibodies against Marek's Disease agent. In addition they produced some fluorescence which behaved in the bird tissues as a specific reaction but was eliminated by absorption with chicken or rabbit liver tissue powder. Therefore, when diagnosing IBV or any other disease in chicken tissue one should be aware of the possibility of extraneous antibodies or antigens even in chickens which appear healthy and are from a specific pathogenfree flock.
TL;DR: Data from experiments designed to detect embryo transmission of Marek's disease (MD) herpesvirus support the feasibility of isolation rearing for the control or eradication of MD.
Abstract: Experiments were designed to detect embryo transmission of Marek's disease (MD) herpesvirus in nine infected breeder flocks No virus was isolated from tissues of 1180 embryos or newly-hatched chicks, and 1487 progeny chicks were all free of infection at hatching as determined by the absence of MD antibody after 9 weeks or more of isolation rearing Furthermore, 8 flocks totaling about 2900 chickens from presumably infected breeder flocks were found serologically negative for MD These data constitute strong circumstantial evidence against embryo transmission and thus support the feasibility of isolation rearing for the control or eradication of MD
TL;DR: An epidemic of dermatitis affecting the skin of the back and thighs of chickens in a large poultry operation was described and the causative organism was shown to be Rhodotorula mucilaginosa.
Abstract: SUMMARY An epidemic of dermatitis affecting the skin of the back and thighs of chickens in a large poultry operation was described. The causative organism was shown to be Rhodotorula mucilaginosa. The same clinical and pathological changes were produced when high doses of the fungus were applied experimentally to plucked areas of healthy chickens. Low doses failed to produce the dermatitis. The pathogenicity and possible immunological response were discussed.
TL;DR: Two-week-old cockerels scored 0, +1, +2, +3, and -4 for lesions produced by Eimeria acervulina respectively gained 55, 51, 44, 35, and 38 grams, which indicates heavy infection, sometimes overlooked because of coalescence of lesions, produces marked reduction in growth rates.
Abstract: Two-week-old cockerels (124 birds) scored 0, +1, +2, +3, and -4 for lesions produced by Eimeria acervulina respectively gained 55, 51, 44, 35, and 38 grams. In a typical controlled experiment, four-week-old cockerels which scored 0, +1.2, +2.8, and +3.8 respectively gained 252, 251, 236, and 167 g in the first week postinoculation. Respective gains four weeks postinoculation were 780, 813, 776, and 681 g. Thus, +1 and (possibly) +2 lesions, commonly recognized as E. acervulina coccidiosis in field cases, should probably be diagnosed as coccidiasis. Heavy infection, sometimes overlooked because of coalescence of lesions, produces marked reduction in growth rates. Suppression of growth rates may appear in infected birds 3-4 weeks postinfection, but they are most apparent one week after inoculation.
TL;DR: It was concluded that M. gallisepticum and M. synoviae could be inactivated when infected hatching eggs reached an internal temperature of 114 F within 12-14 hr if the eggs were started at room temperature (78 F) and the incubator heater was on constantly with no thermostat control.
Abstract: Eggs from chickens experimentally infected with Mycoplasma gallisepticum were heated for 11-15 hr in an incubator containing approximately 2,000 medium-sized eggs and were removed for normal incubation once they reached internal temperatures of 110117 F. After 14 days of normal incubation, all heated and control infected eggs were cultured for M. gallisepticum. Normal control eggs were employed with each heating run to determine hatchability. It was concluded that M. gallisepticum could be inactivated when infected hatching eggs reached an internal temperature of 114 F within 12-14 hr if the eggs were started at room temperature (78 F) and the incubator heater was on constantly with no thermostat control. Hatchability was usually reduced approximately 8-12%o. Results were similar with M. synoviae except that a slightly higher temperature was necessary. It is suggested that just reaching an internal egg temperature of 114.5 F during a 12-to-14-hour preincubation heating period without thermostat control should inactivate M. gallisepticum and M. synoviae in infected chicken hatching eggs.
TL;DR: The diluted serums were more sensitive to changes in conditions of precipitation than the undiluted serums, and minor variations in factors studied, except for NaCl concentration, did not greatly affect the sensitivity of the reaction.
Abstract: SUMMARY Experiments were designed to determine the optimum conditions or reagents for precipitation in agar between Marek's disease cell-culture antigen and antibody in chicken serums. The effects of various agar concentrations and sources, NaCI concentration, buffers, pH, and incubation time and temperature were evaluated with undiluted and serially diluted serums and a standard antigen. The diluted serums were more sensitive to changes in conditions of precipitation than the undiluted serums. Minor variations in factors studied, except for NaCl concentration, did not greatly affect the sensitivity of the reaction. Physiologic salt concentration (0.85%) was greatly inferior to 8% NaCl concentration. The turbidity of high concentrations of agar tended to obscure the precipitin lines partially. The optimum conditions were 1% special agar-Noble, 8% NaCl, NaK phosphate buffer, pH 7.4, and incubation at 37 C for 72 hours.
TL;DR: A passive hemagglutination (HA) test using tanned horse red blood cells coated with partially purified fowlpox viral antigen, obtained by Genetron treatment, was used for titration of antibodies againstfowlpox virus.
Abstract: SUMMARY A passive hemagglutination (HA) test using tanned horse red blood cells coated with partially purified fowlpox viral antigen, obtained by Genetron treatment, was used for titration of antibodies against fowlpox virus. HA antibodies were detected in sera of a few birds as early as 1 week after inoculation, though usually not until the third week after inoculation. HA antibodies were present in the sera of most of the birds up to week 15, when the birds were reinoculated. Agar gel precipitation test first detected precipitating antibodies between the 2nd and 5th weeks after primary inoculation, with persistence for 2 to 5 weeks.
TL;DR: The cultivation of Marek's Disease virus in cell culture and the application of immunofluorescence for virus detection and the preparation of gamma globulins are studied.
Abstract: the preparation of gamma globulins. Proc. Soc. Exptl. Biol. Med. 103:250-252. 1960. 19. Lukert, P. D. Immunofluorescence of avian infectious bronchitis virus in primary chicken embryo kidney, liver, lung and fibroblast cell cultures. Archiv. fur die Gesant Virusforschung. 19:265-272. 1966. 20. Mohanty, S. B., H. M. Devolt, and J. E. Faber. A fluorescent antibody study of infectious bronchitis virus. Poultry Sci. 43:179-181. 1964. 21. Spencer, J. L. The cultivation of Marek's Disease virus in cell culture and the application of immunofluorescence for virus detection. Ph. D. Thesis, New York State Veterinary College, Cornell University. 1969. 22. Wells, A. F., C. E. Miller, and M. K. Nadel. Rapid fluorescein and protein assay method for fluorescent antibody conjugates. Appl. Microbiol. 14:271-275. 1966. 23. Winterfield, R. W., S. B. Hitchner, and G. S. Appleton. Immunological characteristics of a variant of infectious bronchitis isolated from chickens. Avian Dis. 8:40-47. 1964.
TL;DR: D diagnosis of pulmonary mucormycosis in a 9-week-old male chicken, presented for slaughter in good condition, was based on histologic demonstration of the characteristic fungus organism in caseous granulomas.
Abstract: SUMMARY Diagnosis of pulmonary mucormycosis in a 9-week-old male chicken, presented for slaughter in good condition, was based on histologic demonstration of the characteristic fungus organism in caseous granulomas. The organism causing these caseous lesions was differentiated from the causative agent of aspergillosis, which is the most common mycotic lung disease in chickens.
TL;DR: The NP activation test was found to be sensitive, reproducible, easy to perform, and highly reliable.
Abstract: SUMMARY Procedures are described for routine isolation and production of nonproducing Rous sarcoma cells (NP cells) and for use of these cells in the NP activation test for assay of avian leukosis/sarcoma viruses. The NP activation test was found to be sensitive, reproducible, easy to perform, and highly reliable. It required only 5-7 days of cultivation for the activation phase, and 8 days for the RSV assay phase. The sensitivity of the NP activation test for detection of avian leukosis viruses appeared comparable to the COFAL and RIF tests. Because of its relative simplicity and shorter culture periods, a far greater number of samples can be tested in the same period.
TL;DR: In this article, the development of the bacterial flora in the intestines of apparently healthy turkey poults revealed that the alimentary tract is invaded by several bacterial species shortly after hatching and such organisms multiply extensively and reach very high levels within 24-72 hours post-hatching.
Abstract: SUMMARY Techniques were developed for the collection and processing of turkey intestinal material for microflora studies. Repeatable bacteriological procedures were developed which should be applicable to other avian species as well. Studies on the development of the bacterial flora in the intestines of apparently healthy turkey poults revealed that the alimentary tract is invaded by several bacterial species shortly after hatching. Such organisms multiply extensively and reach very high levels within 24-72 hours posthatching. Later, however, bacterial numbers slowly decrease and a characteristic gastrointestinal microflora is established early in life.
TL;DR: Results indicated that litter-sample culturing can be used as a reasonably accurate and practical method for detecting infected flocks and preventing introduction of nonresident salmonella sero-
Abstract: The salmonella status of approximately 280,000 birds, usually extending through 3 generations, was determined on a pen basis by culturing over 48,000 litter samples. Frequency of sample collection ranged from 3 times to weekly throughout life, with sample numbers ranging from 2 to 20 at each sample period depending on the pen population. All birds were maintained in confinement and fed commercially pelleted feed. Houses were cleaned, sprayed with a disinfectant, and new litter added before introducing new populations. Results indicated that litter-sample culturing can be used as a reasonably accurate and practical method for detecting infected flocks. The security management systems used were generally successful in preventing introduction of nonresident salmonella sero-