Protection afforded infectious bronchitis virus-vaccinated sentinel chickens raised in a commercial environment |
| |
| Authors: | J Gelb J K Rosenberger P A Fries S S Cloud E M Odor J E Dohms J S Jaeger |
| |
| Institution: | Department of Animal Science and Agricultural Biochemistry, College of Agricultural Sciences, University of Delaware, Newark 19717-1303. |
| |
| Abstract: | The protective efficacy of three infectious bronchitis virus (IBV) vaccines for sentinel chickens raised with commercial Delmarva broiler chickens was evaluated during winter 1987. Specific-pathogen-free leghorn sentinel chickens were vaccinated with Massachusetts (Mass) alone, Mass and JMK, or Mass and Arkansas (Ark) combination live vaccines, or they remained unvaccinated. Four weeks post-vaccination, sentinels were placed on broiler farms at weekly intervals for 3 weeks corresponding to weeks 4, 5, and 6 of the broiler growing cycle. Vaccine efficacy was evaluated based on IBV reisolation attempts from tracheal swabbings following a 1-week field exposure period. Sentinel chickens vaccinated with Mass and Ark combination vaccine were best protected against IBV field challenge. Only four IBV isolations were made out of a 3-week total of 36 attempts, for an 11% isolation rate. IBV vaccines containing either Mass alone or Mass and JMK offered much lower levels of protection. |
| |
| Keywords: | |
|
|
