Minimizing Salmonella Enteritidis Invasion During Induced Molting

Salmonellosis is one of the most common foodborne diseases with an estimated 800,000 to 4 million human infections reported each year in the United States. During the past 10 to 15 years, the number of cases of gastroenteritis due to Salmonella enterica subspecies enterica serovar Enteritidis (S. Enteritidis) infections has greatly increased in the United States and Europe and by 1995, S. Enteritidis comprised 25% of all foodborne Salmonella isolates. Between 1985 and 1991, over 80% of S. Enteritidis infections in the United States were associated with table eggs and this may be linked to the specific stressful management practice of inducing a molt to stimulate multiple egg-laying cycles in hens. Sixty percent of the estimated 240 million laying hens nationwide are force molted with the practice growing more popular. Feed withdrawal is the primary method used in the layer industry to induce molting. However, feed withdrawal dramatically enhances S. Enteritidis recovery from crops, increases invasion of organs in chickens and increases horizontal transfer in flocks. The poultry industry needs alternative molting procedures that do not require feed withdrawal but allow managers to keep the economic advantages of recycling laying hens by molting without causing a S. Enteritidis contamination problem. The investigators plan to determine whether molt induction diets will minimize S. Enteritidis and if key characteristics in the chicken crop microenvironment can be linked with limiting S.Enteritidis colonization and pathogenesis. This will provide the poultry industry with a scientifically based rationale for possible management alternatives that reduce molting as a major risk for S. Enteritidis contamination.