A number of items of significance to the U.S. egg production industry were published in the June edition of Avian Diseases (Volume 55 # 2)
Gast, R. K. et al. The relationship between the numbers of Salmonella Enteritidis, Salmonella Heidelberg or Salmonella Hadar colonizing reproductive tissues of experimentally infected laying hens and disposition inside eggs. Avian Diseases 55 : 243-247, (2011)
Three serovars of Salmonella were evaluated by the USDA-ARS Egg Safety and Quality Research Unit. Hens were infected orally with large doses of the three organisms and reproductive tissues were examined within a month.