<oL> <LI> Determine if addition of dietary alfalfa will prevent colonization of Salmonella Enteritidis in the crop of chickens undergoing molting and what characteristics in the crop microenvironment are associated with this type of induced molt. <LI> Understand the potential role of the gastrointestinal tract for Salmonella Enteritidis pathogenesis while birds are undergoing molting and if key characteristics in the chicken crop microenvironment can be linked with limiting S. Enteritidis colonization and invasion.
The idea here is to compare the indigenous microbial response in crops of birds that have been molted either by feed deprivation or using an alfalfa diet approach. The hypothesis is that feed intake will be retained in the birds molted via alfalfa addition and the crop microflora will continue to be actively fermenting to the point of being inhibitory to Salmonella Enteritidis colonization and invasion. In addition to enumerating Salmonella Enteritidis recovered after infection in the different treatment groups we plan to quantitate fermentation products and enumerate crop lactobacilli. We will also examine virulence activity of Salmonella Enteritidis.
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 alone. During the past 10-15 years, the number of cases of gastroenteritis due to Salmonella enterica subspecies enterica serovar Enteritidis (SE) infections has greatly increased in the United States and Europe and by 1995, SE comprised 25% of all foodborne Salmonella isolates. Between 1985 and 1991, over 80% of SE 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 SE 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 SE contamination problem. In this proposal our objective is to determine whether an alfalfa molt induction will minimize SE invasion in laying hens. This will provide the poultry industry with a scientifically based rationale for alfalfa as a possible management alternative to reduce molting as a major risk for SE contamination.