THE OCCURRENCE AND DISTRIBUTION OF SALMONELLA TYPES IN FOWL: II. STUDIES OF ARTIFICIAL S. BAREILLY AND S. ORANIENBURG INFECTIONS IN HENS

Abstract

Experimental studies carried out on a limited number of hens infected orally with S. bareilly indicated that occasionally such hens may lay contaminated eggs. Using the estimated numbers of S. bareilly in the feces as the criterion of infection, considerable variation in susceptibility was evident, the carrier period ranging from 5 to 40 days. The organisms were recovered from the intestinal tract and in one instance from the spleen. The apparent development of resistance to repeated oral inoculation was demonstrated. Experiments of a similar nature were made with hens infected orally with S. oranienburg. No contaminated eggs were found, though in this case low egg production resulting from some of the hens moulting reduces the significance of this finding. Fecal counts were lower than those obtained from the S. bareilly infected hens. S. bonariensis was isolated from the feces of two hens during this experiment.