Egg transmission of two strains of Mycoplasma gallisepticum in chickens.

The egg transmissibility of strains F and R of Mycoplasma gallisepticum (MG) was studied in 53 pullets by isolating MG from the eggs and embryos. MG was isolated at rates of 3.19% and 1.59% from the eggs of hens exposed by aerosol to the R or F strain, respectively. However, MG was isolated at rates of 0.19% and 0.00% from the eggs of chickens exposed by eye drop to the R or F strain, respectively. A statistically significant reduction in egg production was observed during the first 4 weeks postexposure in the group exposed to the R strain of MG by aerosol. An unexpected finding was significantly lower fertility of eggs from all MG-infected groups.