Evolutionary Computing for the Radiative-Convective Heat Transfer of a Wetted Wavy Fin Using a Genetic Algorithm-Based Neural Network.

Evolutionary algorithms are a large class of optimization techniques inspired by the ideas of natural selection, and can be employed to address challenging problems. These algorithms iteratively evolve populations using crossover, which combines genetic information from two parent solutions, and mutation, which adds random changes. This iterative process tends to produce effective solutions. Inspired by this, the current study presents the results of thermal variation on the surface of a wetted wavy fin using a genetic algorithm in the context of parameter estimation for artificial neural network models. The physical features of convective and radiative heat transfer during wet surface conditions are also considered to develop the model. The highly nonlinear governing ordinary differential equation of the proposed fin problem is transmuted into a dimensionless equation. The graphical outcomes of the aspects of the thermal profile are demonstrated for specific non-dimensional variables. The primary observation of the current study is a decrease in temperature profile with a rise in wet parameters and convective-conductive parameters. The implemented genetic algorithm offers a powerful optimization technique that can effectively tune the parameters of the artificial neural network, leading to an enhanced predictive accuracy and convergence with the numerically obtained solution.

Thermal performance of Fe3O4, SWCNT, MWCNT and H2O based on magnetohydrodynamic nanofluid flow across a wedge with significant impacts of Soret and Dufour.

The Soret and Dufour effects have significant importance in several practical scenarios, especially in the domain of fluidic mass and temperature transfer. Nanofluidics, biological systems, and combustion processes are all areas where these consequences are crucial. Because of its distinct geometry, a wedge-shaped structure has aerodynamics, production, and engineering applications. Wedge shapes are used in aerodynamics for analyzing and improving airflow across various objects. Nanofluids increase thermal conductivity over traditional fluids making them ideal for cooling high-power electronics, boosting temperature transfer efficiencies, and boosting the solar energy system output. This work is of critical importance since it examines the consequences of a heat source/sink, the Soret impact and the Dufour impact, on the movement of a ternary nanofluid over a wedge. This work uses appropriate similarity constraints to reduce the complexity of the underlying governing equations, allowing for fast computational solutions with the Runge-Kutta-Fehlberg 4-5th order method (RKF-45). Analysis of these phenomena helps determine their possible real-world applications across various engineering fields, by presenting numerical results through plots. The results reveal that adjusting the moving wedge factor lessens the temperature profile, improving the magnetic constraint increases the velocity, and modifying the heat source/sink, Dufour, and Soret factors increases the temperature and concentration profiles. Dufour and heat source/sink constraints speed-up the heat transmission rate. In all cases, ternary nano liquids show significant performance over hybrid nano liquids.

Heat and mass transfer analysis of assisting and opposing radiative flow conveying ternary hybrid nanofluid over an exponentially stretching surface.

Access to dependable and environmentally friendly energy sources is critical to a country's economic growth and long-term development. As countries seek greener energy alternatives, the interaction of environmental elements, temperature, and sunlight becomes more critical in utilizing renewable energy sources such as wind and bioenergy. Solar power has received much attention due to extraordinary efficiency advances. under this context, the present work focus on solar radiation and chemical processes in the presence of modified ternary hybrid nanofluids (THNFs) circulating over an exponentially stretched surface in both aiding flow (A-F) and opposing flow (O-F) circumstances. The primary objective of this investigation is to dive into the complicated dynamics of these structures, which are distinguished by complex interactions involving radiation, chemical reactions, and the movement of fluids. We construct reduced ordinary differential equations from the governing equations using suitable similarity transformations, which allows for a more in-depth examination of the liquid's behavior. Numerical simulations using the Runge-Kutta Fehlberg (RKF) approach and shooting techniques are used to understand the underlying difficulties of these reduced equations. The results show that thermal radiation improves heat transmission substantially under O-F circumstances in contrast to A-F conditions. Furthermore, the reaction rate parameter has an exciting connection with concentration levels, with greater rates corresponding to lower concentrations. Furthermore, compared to the O-F scenario, the A-F scenario promotes higher heat transfer in the context of a modified nanofluid. Rising reaction rate and solid fraction volume enhanced mass transfer rate. The rate of thermal distribution in THNFs improves from 0.13 to 20.4% in A-F and 0.16 to 15.06% in O-F case when compared to HNFs. This study has real-world implications in several fields, including developing more efficient solar water heaters, solar thermal generating plants, and energy-saving air conditioners.

Pullorum Disease: Evolution of the Eradication Strategy.

The history of pullorum disease is closely intertwined with the history of avian health research and that of the poultry industry. The seriousness of the disease galvanized the attention and brought together, for the first time, the pioneers of poultry health research to work cooperatively on different aspects of the disease. Control of the disease made it possible for intensive poultry production to develop as the basis for the modern poultry industry. During the early 1900s, bacillary white diarrhea (BWD) was a devastating disease of young chickens threatening the developing poultry industry. Dr. Leo F. Rettger isolated and described the bacterial pathogen, Salmonella enterica serotype Pullorum, for the first time in 1900. BWD was renamed pullorum disease in 1929. In subsequent years, Rettger and coworkers were able to reproduce the disease and fulfill Koch's postulates. Rettger et al. also showed that Salmonella Pullorum was vertically transmitted, which was the first time that a pathogen was shown to be vertically transmitted. The development of serologic tests was of crucial importance because it led to the development of effective eradication methods to identify carrier birds and to exclude these birds from the breeder flocks. The negative impact of pullorum disease on the poultry industry ultimately was one of the major reasons that the National Poultry Improvement Plan (NPIP) was developed by scientists, the poultry industry, and the United States Department of Agriculture (USDA). Needless to say, the work of the pioneering researchers formed the basis for the control of the disease. The NPIP started in 1935, with 34 states participating in testing 4 million birds representing 58.2% of the birds hatched. The program rapidly expanded to 47 states by 1948 and tested more than 30 million birds. In 1967, all commercial chicken hatcheries participating in the NPIP were 100% free of pullorum and typhoid disease caused by Salmonella enterica serotype Gallinarum. This historical overview of pullorum disease describes in some detail the progress made, especially during the early years, toward controlling this disease using methodologies that were often very basic but nonetheless effective. One has to admire the ingenuity and persistence of the early researchers leading to their achievements considering the research tools that were available at the time.

Artículo histórico­Pulorosis: Evolución de las estrategias de erradicación La historia de la pulorosis está estrechamente relacionada con la historia de la investigación en salud aviar y de la industria avícola. La severidad de la enfermedad despertó la atención y reunió, por primera vez a los pioneros de la investigación en salud avícola para trabajar de manera cooperativa en diferentes aspectos de la enfermedad. El control de la enfermedad hizo posible que la producción avícola intensiva se desarrollara como base de la industria avícola moderna. A principios de la década de los 1900, la diarrea blanca bacilar (con las siglas en inglés BWD) era una enfermedad devastadora de pollos jóvenes que amenazaba la industria avícola en desarrollo. El Dr. Leo F. Rettger aisló y describió el patógeno bacteriano, Salmonella enterica serotipo Pullorum, por primera vez en 1900. La diarrea blanca bacilar pasó a llamarse pulorosis (pullorum disease) en 1929. En los años siguientes, Rettger y sus colaboradores pudieron reproducir la enfermedad y cumplir los postulados de Koch. Rettger y col. también mostraron que Salmonella Pullorum se transmitía verticalmente, y fue la primera vez que se demostró que un patógeno se transmitía verticalmente. El desarrollo de pruebas serológicas fue de crucial importancia porque condujo al desarrollo de métodos de erradicación efectivos para identificar aves portadoras y eliminar a estas aves de las parvadas reproductoras. El impacto negativo de la pulorosis en la industria avícola fue, en última instancia, una de las principales razones por las que los científicos, la industria avícola y el Departamento de Agricultura de los Estados Unidos (USDA) desarrollaron el Plan Nacional de Mejoramiento Avícola (NPIP). Es importante decir que el trabajo de los investigadores pioneros formó la base para el control de la enfermedad. El Plan Nacional de Mejoramiento Avícola comenzó en año 1935, con 34 estados participando en el análisis de 4 millones de aves que representaban el 58.2% de las aves producidas. El programa se expandió rápidamente a 47 estados en 1948 y evaluó a más de 30 millones de aves. En 1967, todas las plantas incubadoras de pollos comerciales que participaban en el Plan Nacional de Mejoramiento Avícola estaban 100% libres de pulorosis y tifoidea aviar causada por Salmonella enterica serotipo Gallinarum. Esta reseña histórica de la pulorosis describe con cierto detalle el progreso realizado, especialmente durante los primeros años, hacia el control de esta enfermedad utilizando metodologías que a menudo eran muy básicas no obstante efectivas. Es admirable el ingenio y la persistencia de los primeros investigadores que los llevaron a sus logros considerando las herramientas de investigación que estaban disponibles en ese momento.

Aflatoxin B1 contamination in wheat grain samples collected from different geographical regions of India: A multicenter study.

In a multicenter study conducted by the Indian Council of Medical Research, 1,646 samples of wheat grain collected from rural and urban areas of 10 states representing different geographical regions of India were analyzed for aflatoxin B1 (AFB1). AFB1 concentrations of > or = 5 microg kg(-1) were recorded in 40.3% of the samples, and concentrations above the Indian permissible regulatory limit of 30 microg kg(-1) were found in 16% of the samples. The proportion of samples with AFB1 concentrations above the Indian regulatory limit ranged from 1.7 to 55.8% in different states, with the minimum in Haryana and the maximum in Orissa. The variation in wheat contamination among states seems to be mainly the result of unsatisfactory storage conditions. Median AFB1 concentrations of 11, 18, and 32 microg kg(-1) were observed in samples from Uttar Pradesh, Assam, and Orissa, respectively; concentrations in other states were <5 microg kg(-1). The maximum AFB1 concentration of 606 microg kg(-1) was observed in a sample from the state of Uttar Pradesh. The calculated probable daily intakes of AFB1 through consumption of contaminated wheat for the population in some states were much higher than the suggested provisional maximum tolerable daily intake. Human health hazards associated with such AFB1 exposure over time cannot be ruled out.

Aflatoxin B(1) contamination of parboiled rice samples collected from different states of India: A multi-centre study.

Under a multi-centre study conducted by the Indian Council of Medical Research, 1,511 samples of parboiled rice were collected from rural and urban areas of 11 states representing different geographical regions of India. These samples were analysed for contamination with aflatoxin B(1.) The presence of aflatoxin B(1) at levels=5 microg g(-1) was found in 38.5% of the total number of samples of the parboiled rice. About 17% of the total samples showed the presence of aflatoxin B(1) above the Indian regulatory limit of 30 microg kg(-1). No statistically significant difference in percentage of samples contaminated with >30 microg kg(-1) was observed between pooled rural (19.4%) and urban (14.5%) data. A median value of 15 microg kg(-1) of aflatoxin B(1) was observed in samples from Assam, Bihar and Tripura. In all other states surveyed the median value was <5 microg?kg(-1).

A wild goose metapneumovirus containing a large attachment glycoprotein is avirulent but immunoprotective in domestic turkeys.

The genomic structure and composition of an avian metapneumovirus (aMPV) recently isolated from wild Canada geese (goose 15a/01) in the United States, together with its replication, virulence, and immunogenicity in domestic turkeys, were investigated. The sizes of seven of the eight genes, sequence identity, and genome organization of goose aMPV were similar to those of turkey aMPV subtype C (aMPV/C) strains, indicating that it belonged to the subtype. However, the goose virus contained the largest attachment (G) gene of any pneumovirus or metapneumovirus, with the predicted G protein of 585 amino acids (aa) more than twice the sizes of G proteins from other subtype C viruses and human metapneumovirus and more than 170 aa larger than the G proteins from the other aMPV subtypes (subtypes A, B, and D). The large G gene resulted from a 1,015-nucleotide insertion at 18 nucleotides upstream of the termination signal of the turkey aMPV/C G gene. Three other aMPV isolates from Canada geese had similarly large G genes, whereas analysis of recent aMPV strains circulating in U.S. turkeys did not indicate the presence of the goose virus-like strain. In vitro, the goose virus replicated to levels (2 x 10(5) to 5 x 10(5) 50% tissue culture infective dose) comparable to those produced by turkey aMPV/C strains. More importantly, the virus replicated efficiently in the upper respiratory tract of domestic turkeys but with no clinical signs in either day-old or 2-week-old turkeys. The virus was also horizontally transmitted to naïve birds, and turkey infections with goose 15a/01 induced production of aMPV-specific antibodies. Challenging day-old or 2-week-old turkeys vaccinated with live goose aMPV resulted in lower clinical scores in 33% of the birds, whereas the rest of the birds had no detectable clinical signs of the upper respiratory disease, suggesting that the mutant virus may be a safe and effective vaccine against aMPV infection outbreaks in commercial turkeys.

Evidence of avian pneumovirus spread beyond Minnesota among wild and domestic birds in central North America.

To detect avian pneumovirus (APV) in central North America, nasal turbinates or choanal deft tissues from domestic turkeys and wild birds were examined for the presence of APV RNA by reverse transcriptase-polymerase chain reaction (RT-PCR), whereas serum samples from domestic turkeys were analyzed for APV antibodies by enzyme-linked immunosorbent assay (ELISA). In 2002, the seroprevalence of disease in domestic turkeys in Minnesota remained high (42.3% of the flocks). In addition, there is evidence the disease has spread to turkey flocks in North Dakota (8.2%), South Dakota (7%), Iowa (10%), and Wisconsin (8.6%) as detected by RT-PCR and/or ELISA. House sparrows and ring-billed gulls sampled in Minnesota and snow geese from Saskatchewan, Canada, were found to harbor APV RNA. Sequence analysis of wild bird APV strains showed high amino acid sequence identity among wild bird isolates (<97%) and between wild bird and turkey viral isolates (93.2%-99.3%). This study demonstrated that APV infections were present in domestic turkey flocks and wild birds outside the state of Minnesota; however, the role of wild birds in spreading APV to domestic turkeys remains unclear.

Survival of Ornithobacterium rhinotracheale in sterilized poultry litter.

Ornithobacterium rhinotracheale (ORT) has been associated with respiratory disease, increased mortality, retarded growth, and decreased egg production in chickens and turkeys. Surveillance of exposure to ORT infection in the field has shown that prevalence of the infection is higher during winter months. The ability of ORT to remain viable in the poultry litter was studied at different temperatures over time. Presterilized poultry litter was inoculated with 10(11) colony-forming units of ORT and kept at -12 C, 4 C, 22 C, 37 C, and 42 C. Reisolation and titration of ORT from litter was attempted at intervals. Results indicate that ORT survived for 1 day at 37 C, 6 days at 22 C, 40 days at 4 C, and at least 150 days at -12 C. ORT did not survive 24 hr at 42 C. The survival of ORT at lower temperatures may be associated with the higher incidence of ORT infection in poultry during winter months.

Detection of avian pneumovirus in wild Canada (Branta canadensis) and blue-winged teal (Anas discors) geese.

Choanal cleft swab samples from 770 wild Canada geese (Branta canadensis) and 358 blue-winged teal (Anas discors), captured for relocation or banding, were examined for the presence of avian pneumovirus (APV) RNA by reverse transcription (RT)-polymerase chain reaction (PCR) and for virus isolation. The swab samples were pooled into groups of 5 or 10. Sixty eight of 102 (66.7%) pooled goose samples were RT-PCR positive for APV RNA. Thirteen of 52 (25.0%) pooled blue-winged teal samples were RT-PCR positive for APV RNA. APV RNA-positive samples were inoculated onto chick embryo fibroblasts (CEF) and QT-35 cells. Infectious APV was isolated from five Canada goose pooled samples in CEF and from one Canada goose pool in QT-35 cells but not from blue-winged teal.

Pathogenesis of avian pneumovirus infection in turkeys.

Avian pneumovirus (APV) is the cause of a respiratory disease of turkeys characterized by coughing, ocular and nasal discharge, and swelling of the infraorbital sinuses. Sixty turkey poults were reared in isolation conditions. At 3 weeks of age, serum samples were collected and determined to be free of antibodies against APV, avian influenza, hemorrhagic enteritis, Newcastle disease, Mycoplasma gallisepticum, Mycoplasma synoviae, Mycoplasma meleagridis, Ornithobacterium rhinotracheale, and Bordetella avium. When the poults were 4 weeks old, they were inoculated with cell culture-propagated APV (APV/Minnesota/turkey/2a/97) via the conjunctival spaces and nostrils. After inoculation, four poults were euthanatized every 2 days for 14 days, and blood, swabs, and tissues were collected. Clinical signs consisting of nasal discharge, swelling of the infraorbital sinuses, and frothy ocular discharge were evident by 2 days postinoculation (PI) and persisted until day 12 PI. Mild inflammation of the mucosa of the nasal turbinates and infraorbital sinuses was present between days 2 and 10 PI. Mild inflammatory changes were seen in tracheas of poults euthanatized between days 4 and 10 PI. Antibody to APV was detected by day 7 PI. The virus was detected in tissue preparations and swabs of nasal turbinates and infraorbital sinuses by reverse transcription polymerase chain reaction, virus isolation, and immunohistochemical staining methods between days 2 and 10 PI. Virus was detected in tracheal tissue and swabs between days 2 and 6 PI using the same methods. In this experiment, turkey poults inoculated with tissue culture-propagated APV developed clinical signs similar to those seen in field cases associated with infection with this virus.

Development, characterization, and preliminary evaluation of a temperature-sensitive mutant of Ornithobacterium rhinotracheale for potential use as a live vaccine in turkeys.

A temperature-sensitive (Ts) mutant strain of Ornithobacterium rhinotracheale (ORT) was developed after exposure of the wild-type organism to N-methyl-N'-nitro-N-nitrosoguanidine. The Ts mutant strain grew at 31 C but had its growth inhibited at 41 C unlike wild-type parent strain. The Ts mutant and parent strains were characterized. Morphologic and biochemical properties of wild-type and mutant strains did not show any differences. The strains were also characterized by polymerase chain reaction (PCR)-based fingerprinting methods. Results showed similar patterns in repetitive sequences by repetitive PCR (enterobacterial repetitive intergenic consensus, highly conserved repeated DNA elements present in Streptococcus pneumoniae (BOX), repetitive extragenic palindromic, and Salmonella enteritidis repetitive element primers); however, random amplified polymorphic DNA fingerprinting was able to differentiate mutant and parent strains showing a unique pattern for each of the ORT strains. The rationale for the use of a Ts strain as a vaccine is based on the ability of the mutant to colonize the upper respiratory tract but not the lower respiratory tract and systemic system of the birds, where the wild-type strain causes severe lesions. In a preliminary evaluation, Ts strain of ORT was recovered from tracheas and choanae of Ts-treated turkeys for 13 days postadministration of the strain either in drinking water or by oculonasal instillation. Humoral immune response was detected in Ts-vaccinated but not in control group birds after 3 wk postadministration. Results suggest that Ts strain of ORT has promising potential use as a live vaccine for ORT.

Neonatal avian pneumovirus infection in commercial turkeys.

Eleven market turkey flocks developed a respiratory disease characterized by coughing, swollen sinuses and nasal discharge. These symptoms first appeared between 3 and 16 days of age. Avian pneumovirus (APV) RNA was detected by reverse transcriptase (RT)-polymerase chain reaction (PCR) in six of six flocks tested. APV was detected by immunohistochemistry in turbinates of three of three affected flocks tested. Virus isolation attempts were negative. Ten of 11 flocks became seropositive on the APV enzyme-linked immunosorbent assay. Five weeks prior to hatch of these affected market turkeys, several breeder flocks in one geographic area had developed clinical signs and experienced decline in egg production typical of APV infection. In two breeder flocks, acute and convalescent sera indicated APV infection during the period of declining egg production. Attempts to detect APV RNA by RT-PCR from choanal cleft swabs of newly hatched poults were successful. Attempts to isolate the virus from these PCR-positive samples were negative.

Susceptibility of ducks to avian pneumovirus of turkey origin.

OBJECTIVE: To determine the susceptibility of ducks to avian pneumovirus (APV) of turkey origin. ANIMALS: 30 Pekin ducks that were 2 weeks old. PROCEDURE: Ducks were assigned to 3 groups (10 ducks/group). Ducks of groups 1 and 2 were inoculated (day 0) with 200 microl of cell-culture fluid containing APV of turkey origin (10(5.5) median tissue-culture infective dose/ml) by the oculonasal (group 1) or oral (group 2) route. Ducks of group 3 served as noninoculated control birds. Two ducks from each group were euthanatized 3, 6, 9, 15, and 21 days after inoculation. Blood samples, tissue samples from the lungs, trachea, nasal turbinates, duodenum, diverticulum vitellinum (Meckel's diverticulum), and cecum, and swab specimens from the choana, cloaca, and trachea were obtained from all birds during necropsy and examined for APV by use of reverse transcriptase-polymerase chain reaction (RT-PCR), virus isolation, and histologic examination. Blood samples also were examined for APV antibodies, using an ELISA. RESULTS: Tissue samples obtained up to 21 days after inoculation had positive results when tested by use of RT-PCR. Virus was isolated from nasal turbinates of birds inoculated via the oculonasal route. Serum samples obtained 15 and 21 days after inoculation had positive results when tested for APV-specific antibody. Clinical signs of disease were not observed in ducks inoculated with APV of turkey origin. CONCLUSIONS AND CLINICAL RELEVANCE: Ducks inoculated with APV of turkey origin may not develop clinical signs of disease, but they are suspected to play a role as nonclinical carriers of APV.

Immunohistochemical detection of avian pneumovirus in formalin-fixed tissues.

An immunohistochemical staining technique (IHC) was developed to detect avian pneumovirus (APV) antigen in formalin-fixed, paraffin-embedded tissue sections using streptavidin-biotin immunoperoxidase staining. Samples of nasal turbinates and infraorbital sinuses were collected from 4-week-old poults experimentally inoculated with APV and from older turkeys infected during naturally occurring outbreaks of avian pneumovirus. Tissue was fixed in 10% buffered neutral formalin, embedded in paraffin, sectioned and stained. Inflammatory changes were observed microscopically in the mucosa and submucosa of the nasal turbinates and infraorbital sinuses of both experimentally inoculated poults and naturally infected birds. Viral antigen was detected by IHC in the ciliated epithelial cells of nasal turbinates and infraorbital sinuses.

Vaccination of turkeys with an avian pneumovirus isolate from the United States.

Four-week-old poults obtained from avian pneumovirus (APV) antibody-free parents were vaccinated with different serial 10-fold dilutions of cell culture-propagated APV vaccine. The birds were vaccinated with 50 microl into each conjunctival space and nostril (total of 200 microl). Each poult of each group was vaccinated in groups that received doses of 4 x 10(4), 4 x 10(3), 4 x 10(2), 4 x 10(1), or 4 x 10(0) 50% tissue culture infective dose (TCID50) of APV vaccine, respectively. Respiratory signs were seen between 3 and 12 days postvaccination (PV) in the poults that were vaccinated with 4 x 10(4), 4 x 10(3), and 4 x 10(2) TCID50, respectively. In these groups, APV was detected from swabs collected at 5 days PV and seroconversion was detected at 2 wk PV. The groups that were originally vaccinated with 4 x 10(1) and 4 x 10(0) TCID50 developed mild clinical signs after vaccination, but neither virus nor antibody was detected PV. At 2 wk PV (6 wk of age), birds from each group, along with five unvaccinated controls, were challenged with APV. Upon challenge, the 4 x 10(4) and 4 x 10(3) TCID50 groups were protected against development of clinical signs and were resistant to reinfection. The group previously vaccinated with 4 x 10(2) TCID50 developed clinical signs after challenge that were considerably milder than those seen in the groups that had previously been vaccinated with lower doses or no virus. Even though 4 x 10(2) TCID50 vaccine dose administered by intranasal ocular route resulted in infection, incomplete protection resulted with this pivotal dose. Upon challenge, the 4 x 10(1) and 4 x 10(0) TCID50 groups exhibited milder disease signs than those seen in the challenged unvaccinated controls. In these groups, APV was detected in preparations of swabs collected at 5 days postchallenge (PC) and seroconversion was detected at 2 wk PC. These results indicate that the dose of APV vaccine that causes protection is higher than that required to produce infection.

Seroprevalence of Ornithobacterium rhinotracheale infection in commercial laying hens in the north central region of the United States.

This study was the first to examine the seroprevalence of Ornithobacterium rhinotracheale (ORT) within a commercial egg layer population. Serum samples collected from egg production companies were examined by serum plate agglutination test (SPAT) and outer membrane protein-based enzyme-linked immunosorbent assay (ELISA). Results show that 90% of layer flocks were positive by SPAT and 100% by ELISA. Of the pullet flocks examined, 43% and 52% were positive by SPAT and ELISA, respectively. Our study indicates that the prevalence of ORT antibody is high in the commercial layer population, suggesting that this respiratory pathogen can easily spread through multiple-age layer farms from older flocks to newly housed pullet flocks.

Avian pneumovirus (APV) RNA from wild and sentinel birds in the United States has genetic homology with RNA from APV isolates from domestic turkeys.

Nasal turbinates or swabs were collected from wild ducks, geese, owls, sparrows, swallows, and starlings and from sentinel ducks placed next to turkey farms experiencing avian pneumovirus (APV) infections and were analyzed for APV genome and infectious particles. APV RNA was detected in samples examined from geese, sparrows, and starlings. APV RNA and antibodies were also detected in two different groups of sentinel ducks. Infectious APV was recovered from sentinel duck samples. The APV M gene isolated from the wild birds had over 96% predicted amino acid identity with APV/Minnesota 2A, which was isolated earlier from domestic turkeys showing respiratory illness, suggesting that wild birds may be involved in spreading APV infection.

Ornithobacterium rhinotracheale infection in turkeys: immunoprophylaxis studies.

Ornithobacterium rhinotracheale has been shown to cause serious clinical illness and is a significant concern to the turkey industry because of its potential economic impact. In this study, 6-wk-old turkeys were vaccinated intranasally with a live or subcutaneously with a killed O. rhinotracheale vaccine. At 14 or 21 wk of age, the birds were challenged intratracheally with live O. rhinotracheale. Airsacculitis and pneumonia occurred less frequently in vaccinated birds than in unvaccinated birds after challenge with O. rhinotracheale. Ornithobacterium rhinotracheale was recovered from unvaccinated, challenged birds but not from vaccinated, challenged or from unchallenged birds. Thus, turkeys inoculated with live or killed O. rhinotracheale vaccine were protected from pathologic changes.

Ornithobacterium rhinotracheale infection in commercial laying-type chickens.

Ornithobacterium rhinotracheale is a gram-negative, rod-shaped, pleomorphic bacterium that has been isolated from flocks of turkeys and broilers from around the world. Infections cause respiratory disease, mortality, and growth suppression, or clinical signs of infection may be absent. In layers, there have been few reports of disease caused by O. rhinotracheale. This is the first report of O. rhinotracheale infection in United States layer flocks.