Salmonella in the Laying Hen

ABSTRACT A study was made to determine the fate of Samonella organisms after in-gestion by the laying hen. Three species of Salmonella were used, i.e., senftenberg, thompson and typhimurium. Approximately one million cells of each species were introduced into the crop of 12 White Leghorn type laying hens for 10 days. The trials involving each species were carried out consecutively with thorough disinfection of equipment between trials. From each hen, feces and eggs were analyzed daily for Salmonella for the 10 day period. At the end of the 10 day trial a sample of blood was drawn from each hen for Salmonella analysis. In addition, the hens were slaughtered and a sample of the ovaries, kidneys, heart, liver and lungs was aseptically removed for analysis. Results showed that approximately 25 % of the fecal samples were found to contain the species of Salmonella under study. The percentage of positive recoveries from egg shells was less than 10 % for all three species studied. Among the egg contents examined for all three species, only one egg yielded a positive recovery. All tissue samples were found to be negative. It was concluded that there was no contamination of body tissues even after con-tinuous ingestion of large doses of Salmonella organisms. Neither was there a problem of egg meat contamination among intact eggs