EVALUATION OF RESISTANCE OF 4 STRAINS OF COMMERCIAL LAYING HENS TO EXPERIMENTAL-INFECTION WITH SALMONELLA-ENTERITIDIS PHAGE TYPE-8

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 bi rds were monitored for 10 wk postinfection for colonization of interna l organs, fecal shedding of S. enteritidis, and the production of S. e nteritidis-contaminated eggs. There was no difference among the four h en strains in regards to the probability of S. enteritidis isolation f rom liver and spleen., ovary, and cecal tissue within the first 30 d p ostinfection. However, during the first 14 d postinfection, S. enterit idis organisms were isolated in significantly higher rates from eggs a nd fecal samples of Strain A than from samples obtained from the other three hen strains. Results suggest that there may be inherent differe nces between strains of laying hens with regard to their response to i nfection with S. enteritidis.