Genetic line differences in survival and pathogen load in young layer chicks after Salmonella enterica serovar enteritidis exposure

Early infection may result in long-term colonization of layers with Salmone lla enterica sv. enteritidis (S. enteritidis, SE), resulting in shedding in to table or hatching eggs. To evaluate genetic factors underlying early res ponse to SE, genetic line differences in mortality and pathogen load at two sites (cecal lumen and spleen) were investigated. At day of hatch, chicks of four genetic lines were intra-esophageally inoculated with one of three doses of SE phage type 13a. There was a significant effect (P < 0.001) of g enetic line on chick 6-d survival. The effect of genetic line was significa nt (P < 0.05) on survivors' SE burden in cecal content but not on SE burden per gram of spleen. The SE pathogen load of the spleen and the cecal conte nt were not significantly correlated, indicating that independent host mech anisms are partly responsible for these two traits. Genetic line difference s in chick survival and SE colonization of cecal content were demonstrated in young layer chicks.