Transmission Dynamics of Respiratory Microorganisms in Backyard Chickens

PI: Patti Miller; CO-PI: Claudio L. Afonso and Corrie C. Brown

Objective: Establish that the transmission of respiratory microorganisms in backyard chickens is reduced statistically when contact between poultry and Georgia songbird species are inhibited through the use of 24-hour coop biosecurity, even if cooped poultry are infectious to wild avian species. Here contact is defined as any mode of interspecific interaction leading to the successful transmission of respiratory microorganisms, including the experimental microorganism serving as the proxy virus, the live LaSota Newcastle disease virus vaccine

General Description: In the one year period, the following tasks will be performed and the expected outcomes will be generated. Prior to the LaSota-Chicken treatment, the area around experimental setting will be mist-netted for capturing 20% of the resident wild birds and tested for the presence of incidentally circulating NDV. Andrea Ayala, a PhD student who holds all the necessary ornithological state and federal licenses/permits will proceed to color band, attach RFID tags, bleed, and swab resident songbirds to ensure ‘wild-type’ NDV does not interfere with the experimental NDV inoculation. The plot of land will then be divided into two subplots in which each coop is separated by 400 meters. Poultry in Treatment B1 will be inoculated with the LaSota vaccine and allowed to free-range daily. Poultry in Treatment B2, the control, will also be inoculated with the LaSota vaccine, however, they will not be allowed to free-ranged. Songbirds within 100 meters of each coop will be captured, re-bled for antibodies, and swabbed for the presence of vaccine and additional respiratory microorganisms. Birds without previously attached RFID tags (from the sampling of the wild birds prior to starting the experiment) will have new ones placed. After one month, chickens will have seroconverted and the number of microbe transmission events from chickens to songbirds in each plot will be calculated. Swabs from wild birds and chickens will be analyzed using real-time RT PCR. Using G*Power analysis, It is expected that at least 200 songbirds representing minimum sample sizes of four wild bird species with at least 30 individuals per treatment will be captured. HI antibody levels to NDV, and relative quantitative real time RT-PCR data will be completed. Data from the RFID tags will start to be compiled and the Next Gen Sequencing (NGS) will start to be processed. However, it is likely that the RFID tag data and complete NGS data will not be completed until the second year.


abundo.1Project Miller