Probability of survival based on ELISA titer following challenge of vaccinated chickens with the X-73 strain of Pasteurella multocida.
The probability of survival of chickens following a challenge dose of the X-73 strain of Pasteurella multocida was calculated based on enzyme-linked immunosorbent assay (ELISA) titer. Chickens were vaccinated subcutaneously with the Clemson University strain of P. multocida. On days 3, 5, 7, 10, 12, 14, 21, and 28 post-vaccination, 10 vaccinated chickens and 5 unvaccinated controls were selected at random, bled, and then challenged with 2000 colony-forming units of X-73. The ELISA titers to P. multocida vaccination and responses to challenge were recorded. A logistic procedure predicted probability of survival related to ELISA titer. The ELISA titer and survival were highly correlated. A flock profile for each day of challenge was developed based on a probability of survival (PS) at the following levels: PS less than 25%, 25% less than or equal to PS less than 50%, 50% less than or equal to PS less than 75%, and PS greater than or equal to 75%. The antibody response of the chickens through 28 days post-vaccination demonstrated a classic response to vaccination.
D000818:Animals; D002645:Chickens; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D010326:Pasteurella Infections / Q000276:immunology / Q000401:mortality / Q000662:veterinary*; D011201:Poultry Diseases / Q000276:immunology* / Q000401:mortality; D011336:Probability; D014612:Vaccines / Q000008:administration & dosage*
D014612:Vaccines