Project Number: 6612-32000-063-15
Project Type: Trust

Start Date: Oct 01, 2011
End Date: Jun 30, 2014

Objective:
1. Develop a protocol for the recovery and determination of virus titer for four Infectious Bursal Disease Viruses artificially-inoculated chicken and turkey meat. 2. Develop thermal inactivation curves for infectious bursal disease virus in artificially-inoculated chicken and turkey meat. 3. Determine infectious bursal disease virus titers in breast and thigh meat, thymus and cloacal bursal of chickens inoculated with one of four viruses. 4. Determine thermal inactivation times and temperatures for naturally infected chicken meat and cloacal bursal tissue.

Approach:
1. Artificially infected meat (breast and thigh meat) will be prepared by injecting 1 µl of allantoic fluid containing the virus into the center of packed meat or tissue samples (0.05g). Sample will be maintained at 4C. The concentration of virus in chicken meat and tissue will be determined following the artificial inoculation. Thermal inactivation curves will be generated from which decimal reduction times (D value) and change in thermal resistance (zD values) will be calculated. D-values for 4 infectious bursal disease viruses in artificially inoculated chicken meat will be calculated following thermal treatment at 74C, 75C, 78C, and 80C for 0, 5, 10, 20, 30, 45, 60 and 100 min. 2. Groups of fifteen 4 -week-old chickens will be orally infected with one of four infectious bursal disease viruses to simulate a natural route of infection. At 2, 4, 7, 14 and 21 days after inoculation chickens will be sampled with collection of breast and thigh meat, thymus and cloacal bursa. Samples will be frozen at -70C until used. Tissue samples from naturally-infected chickens (0.05g) will be dispensed into thin walled PCR tubes and centrifuged to pack the meat into the bottom of the tube. Samples will be taken from 3 chickens on 2, 4, 7, 14 and 21 days after inoculation for testing via virus quantification methods. 3. Thermal inactivation curves will be generated from which decimal reduction times (D value) and change in thermal resistance (zD values) will be calculated. D-values for 4 IBDV viruses in natural infected chicken meat and cloacal bursa tissue will be calculated following thermal treatment at 74C, 75C, 78C, and 80C for 0, 5, 10, 20, 30, 45, 60 and 100 min.