Changes in the Transcriptome Profile in Young Chickens after Infection with LaSota Newcastle Disease Virus.

Understanding gene expression changes in chicks after vaccination against Newcastle Disease (ND) can reveal vaccine biomarkers. There are limited data on chicks' early immune response after ND vaccination. Two trials focused on this knowledge gap. In experiment one, 42 13-day-old specific-pathogen-free (SPF) chicks were used. Harderian glands (Hgs) and tracheas (Tcs) from five birds per group were sampled at 12, 24, and 48 h post-vaccination (hpv) to evaluate the gene transcription levels by RNA sequencing (RNA-seq) and RT-qPCR. The results of RNA-seq were compared by glmFTest, while results of RT-qPCR were compared by t-test. With RNA-seq, a significant up-regulation of interferon-related genes along with JAK-STAT signaling pathway regulation was observed in the Hgs at 24 hpv. None of the differentially expressed genes (DEGs) identified by RNA-seq were positive for RT-qPCR. Experiment 2 used 112 SPF and commercial chickens that were 1 day old and 14 days old. Only the commercial birds had maternal antibodies for Newcastle Disease virus (NDV). By RNA-seq, 20 core DEGs associated with innate immunity and viral genome replication inhibition were identified. Genes previously unlinked to NDV response, such as USP41, were identified. This research present genes with potential as immunity biomarkers for vaccines, yet further investigation is needed to correlate the core gene expression with viral shedding post-vaccination.

A meta-analysis of the effect of Eimeria spp. and/or Clostridium perfringens infection on the microbiota of broiler chickens.

Coccidiosis in chickens is caused by Eimeria spp. The infection provides a growth advantage to Clostridium perfringens (CP), frequently leading to necrotic enteritis. One approach to alleviate the negative impacts of the diseases is to improve the bacterial composition in chickens, and many experiments investigating chicken enteric health in recent years include the characterization of the bacterial microbiota. This meta-analysis synthesized the data of studies investigating the intestinal microbiota after infection with coccidia and/or CP to provide a basis for future research. Inclusion criteria were that experiments contained a group infected with one or both pathogens and an uninfected control group, the use of 16SrRNA Illumina sequencing and the availability of raw data. A total of 17 studies could be included. Meta-analyses of 3 different data sets were performed: 1 on data of 9 experiments on chickens infected with coccidia only; the second on data of 4 studies on chickens infected with CP only; the third on raw data of 8 experiments with chickens infected with coccidia and CP. The meta-analysis of relative abundance and alpha diversity of the data sets was performed in R using the SIAMCAT and metafor packages. The number of families of interest identified by the analyses of experiments with infection with coccidia only, CP only and the combined infection were 23, 2, and 29, respectively. There was an overlap of 13 families identified by analyses of experiments with infection with coccidia only and of experiments with the combined infections. Machine learning was not able to find a model to predict changes of the microbiota in either 1 of the 3 analyses. Meta-analyses of functional profiles showed a more uniform reaction to the infections with the relative abundance of many pathways significantly altered. Alpha diversity was not affected by infection with either pathogen or the combination. In conclusion, the heterogeneity of these microbiota studies makes recognizing common trends difficult, although it seems that coccidia infection affects the microbiota more than an infection with CP. Future studies should focus on the bacterial functions that are changed due to these infections using metagenome techniques.

Effects of dietary yeast cell wall supplementation on growth performance, intestinal Campylobacter jejuni colonization, innate immune response, villus height, crypt depth, and slaughter characteristics of broiler chickens inoculated with Campylobacter jejuni at d 21.

A study was conducted to assess the effects of a dietary yeast cell wall (YCW) with and without a Campylobacter jejuni (CJ) challenge. A total of 2,240-day-old Ross 708 males were randomly assigned within 8 treatments with a 4 × 2 factorial design, with 4 diets (negative control, positive control, YCW constant dose (400 g/ton), and YCW step-down dose (800/400/200 g/ton in the starter/grower/finisher diets, respectively) and with and without d 21 CJ oral gavage challenge at 5.2 × 107 CFU/mL. At d 0, 14, 28, and 41 body weights and feed consumption were measured to determine performance. At d 14, 28, and 42, 8 jejunal and ileal histology samples per treatment were collected for villi morphology measurements. At d 22 and 28 (1- and 7-days postinoculation), 24 ileal tissue samples per treatment were collected for relative gene expression analysis. At d 42, 24 cecal content samples per treatment were collected for CJ enumeration. Finally, on d 44, 96 birds per treatment were processed to determine carcass yield and 16 carcass rinses per treatment were collected to determine CJ prevalence after processing. Diet or inoculation did not impact broiler performance (P > 0.05). Limited differences were observed in intestinal morphology, and villus height and crypt depth were different only in the ileum at d 42 (P = 0.0280 and P = 0.0162, respectively). At d 1 postinoculation, differences between treatments inoculated with CJ and PBS were observed in the expression of avian beta defensin 10 (AvBD10), interleukin 1ß (IL-1ß), and interleukin 10 (IL-10) (P < 0.05). At d 7 postinoculation, expression of AvBD10, IL-1ß, and IL-10 was similar among all treatments (P > 0.05). At d 42, all birds, regardless the inoculation, had similar levels of CJ recovered from cecal contents (P > 0.05). After processing, carcass yield and CJ prevalence postchilling was similar in all treatments (P > 0.05). Overall, under the conditions of this study, the addition of YCW during a CJ challenge did not have an impact in growth performance, innate immune response, cecal colonization, carcass yield, or CJ prevalence after processing.

Infection with Ascaridia galli Does Not Significantly Alter Intestinal Microbiota and Is Cleared After Changes in the Expression of Cytokines.

Because of the trend of cage-free egg production, infections with the nematode Ascaridia galli are receiving increased attention. The aim of this study was to establish a timeline for the influence of A. galli on the expression of key cytokines related to a parasitic immune response, and on the composition of the jejunal microbiota. Twenty-eight male layer-type birds were challenged at 24, 25, and 26 days of age. An additional 28 birds were kept as uninfected controls. Starting on Day 31, three birds of each group were euthanized every week until 8 wk postinfection (PI). The number of larvae isolated from the intestinal wall decreased over time, until no larvae were seen at 7 and 8 wk PI. At 5 wk PI, there was a numerical upregulation of all cytokines (TGF-ß, IFN-γ, IL-4, IL-8, IL-10, IL-13) in the infected group, but this change was only statistically significant for IL-13. At this time point, larvae were expected to have developed into adults that would have shed eggs in the feces. However, no adult worms were seen and there was no egg shedding. For the microbiota analysis, there were significant differences in the alpha diversity (Faith's phylogenetic diversity) between challenge and control groups, and the beta diversity analysis showed slight differences between samples, suggesting that the age of the birds was the main reason for the separation of groups. These findings suggest that the upregulation of all cytokines evaluated in Week 5 might be the reason for resolution of the infection. Possible explanations are that a high infection dose and the fact that birds were fed with a more nutritionally dense feed might have contributed to the birds' immune system clearing the infection before the worms were able to reach maturity.

La infección por Ascaridia galli no altera significativamente la microbiota intestinal y se elimina tras cambios en la expresión de citocinas. Debido a la tendencia de la producción de huevos libres de jaulas, las infecciones con el nematodo Ascaridia galli están recibiendo una mayor atención. El objetivo de este estudio fue establecer una línea de tiempo para la influencia de A. galli en la expresión de citoquinas clave relacionadas con una respuesta inmune parasitaria y en la composición de la microbiota yeyunal. Veintiocho aves macho de tipo postura fueron desafiadas a los 24, 25 y 26 días de edad. Se mantuvieron 28 aves adicionales como controles no infectados. A partir del día 31, se practicó la eutanasia a tres aves de cada grupo cada semana hasta las 8 semanas posteriores a la infección (PI). El número de larvas aisladas de la pared intestinal disminuyó con el tiempo, hasta que no se observaron larvas a las 7 y 8 semanas después de la infección. A las cinco semanas post-infección, hubo una regulación ascendente numérica de todas las citoquinas (TGF-ß, IFN-γ, IL-4, IL-8, IL-10, IL-13) en el grupo infectado, pero este cambio solo fue estadísticamente significativo para IL-13. En ese momento, se esperaba que las larvas se hubieran convertido en adultos que eliminarían huevos en las heces. Sin embargo, no se observaron nemátodos adultos y no hubo eliminación de huevos. Para el análisis de microbiota, hubo diferencias significativas en la diversidad alfa (diversidad filogenética de Faith) entre los grupos de desafío y control y el análisis de diversidad beta mostró ligeras diferencias entre las muestras, lo que sugiere que la edad de las aves fue la razón principal de la separación de los grupos. Estos hallazgos sugieren que la regulación al alza de todas las citocinas evaluadas en la semana 5 podría ser el motivo de la resolución de la infección. Las posibles explicaciones son que una dosis alta de infección y el hecho de que las aves fueran alimentadas con un alimento más denso desde el punto de vista nutricional podrían haber contribuido a que el sistema inmunitario de las aves eliminara la infección antes de que los nemátodos pudieran alcanzar la madurez.

Analysis of Information for Backyard Flock Owners Provided by Extension Websites.

Early recognition and prevention of infectious diseases in poultry flocks are essential to reduce spread from bird to bird, to prevent zoonoses, and to keep losses low. Backyard flock owners often have little knowledge about poultry health, and specialized veterinarians are difficult to find. Alternative sources for support, education, and training for noncommercial poultry are the websites of cooperative extension services offering online webinars, presentations, and programs about poultry health and diseases. The aim of this investigation was to survey 23 websites of the extension services of the top 13 states in poultry production for information on backyard poultry health. The eXtension website by the United States Cooperative Extension System was added as a nation-wide source of information. Structure, content, and presentation form were compared and analyzed. The results displayed large differences between the investigated webpages and identified opportunities for improving the sites, especially in completeness, accessibility, and presentation of the information. From 23 extension websites, 13 provided none to very limited online information and 5 websites covered almost all of the investigated content. The primary media used were articles with pictures, and only three universities added videos and webinars. Based on these results and according to the increased need for online sources about poultry health, the extension websites should provide complete and correct information or at least links to approved sources. Videos, podcasts, and webinars can increase outreach and learning achievement. This survey may help to improve the presentation and content of poultry health-related extension websites.

Análisis de la información disponible para propietarios de parvadas de traspatio proporcionada por páginas de extensión en la red internet. El reconocimiento temprano y la prevención de enfermedades infecciosas en las parvadas avícolas son esenciales para reducir su propagación entre aves, para prevenir las zoonosis y para mantener posibles pérdidas bajo control. Los propietarios de parvadas de traspatio a menudo tienen poco conocimiento sobre salud avícola y es difícil encontrar veterinarios especializados. Las fuentes alternativas de apoyo, educación y capacitación para aves de corral no comerciales son las páginas en la red internet preparadas por los servicios de extensión cooperativa que ofrecen seminarios en línea, presentaciones y programas sobre salud y enfermedades de las aves de corral. El objetivo de esta investigación fue analizar 23 páginas en la red internet de los servicios de extensión de los 13 estados principales en producción avícola para obtener información sobre la salud de las aves de corral de traspatio. La página de internet eXtension del Sistema de Extensión Cooperativa de los Estados Unidos se agregó como fuente de información a nivel nacional. Se compararon y analizaron la estructura, el contenido y la forma de presentación. Los resultados mostraron grandes diferencias entre las páginas de internet investigadas y se identificaron oportunidades para mejorar los sitios, especialmente en cuanto a la profundidad, accesibilidad y presentación de la información. De 23 páginas de extensión en la internet, 13 proporcionaron ninguna o muy poca información en línea y cinco páginas cubrieron casi la totalidad del contenido investigado. Los medios principales utilizados fueron artículos con imágenes y solo tres universidades agregaron videos y seminarios en línea. Con base en estos resultados y de acuerdo con la creciente necesidad de fuentes en línea sobre salud aviar, las páginas de extensión en la internet deben proporcionar información completa y verídica o al menos enlaces con fuentes aprobadas. Los videos, cápsulas informativas en línea también denominadas "podcasts" y seminarios en línea pueden aumentar el alcance y los logros de aprendizaje. Esta encuesta puede ayudar a mejorar la presentación y el contenido de las páginas de extensión en la internet que están relacionadas con la salud avícola.