Submitted to: Avian Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/23/2001
Publication Date: N/A
Interpretive Summary: The commercial egg industry has numerous mycoplasma which infect the hens. As depopulation of these complexes "never" occurs, all of the hens eventually become infected. Because mycoplasmas have no cell wall, they are not removed by the administration of antibiotics. To combat these organisms in layer chickens, the industry uses vaccines. However, little is currently known about the vaccines, particularly as they impact egg production, eggshell quality and egg size distribution. This study determined that the vaccine strain known as 6/85 does not detrimentally affect egg production, any of the selected egg and eggshell quality parameters, nor does it skew egg size distribution. With this information, producers can use this vaccine and not be concerned about negative or detrimental impacts on their flocks or the eggs they produce.
Technical Abstract: Live Mycoplasma gallisepticum (MG) vaccines have been USDA approved and licensed for use in commercial layer chickens since 1988. Scant information is available pertinent to the effects of 6/85 MG on egg and eggshell quality parameters, as well as egg size distribution. In this study, hen-day egg production, eggshell strength, Haugh unit score, pimpling incidence and blood/meat spot incidence were monitored and recorded in each trial through a 43-wk production cycle. Further, eggs from all treatments were collected daily, Monday-Thursday, and individually weighed. No significant difference was observed between the treatments for the parameters measured or for egg size distribution with the exception of the jumbo-sized egg class which were laid in greater numbers by hens vaccinated with 6/85 MG at 10 wk of age. These data should lessen producers' concerns pertaining to the impact of 6/85 strain MG on egg production, egg and eggshell quality parameters, and egg size distribution.