Evaluation of resistance of four strains of commercial laying hens to experimental infection with Salmonella enteritidis phage type eight.

Four different strains of White Leghorn hens were orally infected with 1 x 10(8) cfu of Salmonella enteritidis phage Type 8 per bird. The birds were monitored for 10 wk postinfection for colonization of internal organs, fecal shedding of S. enteritidis, and the production of S. enteritidis-contaminated eggs. There was no difference among the four hen strains in regards to the probability of S. enteritidis isolation from liver and spleen, ovary, and cecal tissue within the first 30 d postinfection. However, during the first 14 d postinfection, S. enteritidis organisms were isolated in significantly higher rates from eggs and fecal samples of Strain A than from samples obtained from the other three hen strains. Results suggest that there may be inherent differences between strains of laying hens with regard to their response to infection with S. enteritidis.