Evaluation of Efficacy of PoulShot^® MG-F Vaccine against Mycoplasma gallisepticum Infection in the Layer Farms

Abstract

Mycoplasma gallisepticum (MG) infection results in severe economic loss in the poultry industry. In the previous reports, F strain, one of the MG live vaccine strains, could protect the bird from field infection of MG strains. In this study, efficacy of PoulShot Ⓡ MG-F vaccine againset mycoplasma gallisepticum infection was evaluated for filed application in commercial layers.Commercial layers from two different farms received with PoulShot Ⓡ MG-F, MG-F live vaccine at 9～14 weeks of age. Serological immune response to MG vaccine, the persistency of MG vaccine strain in the upper respiratory tracts and egg production rate were evaluated in the vaccinated, contacted or nonvaccinated flocks. The serological response was first detected at 3 weeks after vaccination (WAV) and persisted for 31 WAV. The MG vaccine strains were also persisted for 31 WAV based on the reisolation and PCR detection. There was no difference between the vaccinated or non-vaccinated flocks in the egg production rate but in the abnormality rate of eggs. Based on the above results, we suggested that the PoulShot Ⓡ , MG-F live vaccine was fully immunogenic and had characteristics of long persistence in the upper respiratory trachea which will reduce economic loss caused by MG infection in the layer farms.( (Papazisi et al., 2002).