Decreased hatchability of turkeys eggs caused by experimental infection with Mycoplasma meleagridis

Turkey eggs experimentally infected with Mycoplasma meleagridis (MM) showed a significant (p less than 0.05) decrease in production of first-quality poults of approximately 20% when compared with uninoculated controls and a placebo group of eggs. Embryo mortality was highest between the time the eggs were transferred from incubator to hatcher (25 days of incubation) and the time the embryos hatched. Risk of embryo mortality associated with infection in this late incubation period for the MM-infected embryo was more than double the risk for uninfected embryos. The number of dead-in-shell and pipped embryos was almost 10% higher than the number found in either control or placebo groups. There appeared to be a stress due to the inoculation of both the placebo and the organism, increasing embryo mortality between 9 and 24 days of incubation. However, this effect was not evident after transfer. Total economic loss associated with decreased hatchability caused by MM and the cost of a control program were estimated to be $9.4 million per year in the United States.