Does the Inclusion of Distiller Dried Grains with Solubles in the Diet of Pigs Affect Susceptibility To/colonization with Salmonella

Approach:
This project will be conducted with the objective of determining if inclusion of DDGS in the diet of grow-finishing pigs affects their susceptibility to Salmonella as well as the colonization pattern of their intestinal tract and longitudinal shedding of Salmonella. Two experiments will be conducted to achieve this complex objective. In the first experiment, a total of 36 pigs (divided in two replicates or blocks) will be used to compare three treatments (Control/No DDGS, 20% DDGS, and 40% DDGS inclusion in the diet). After an adaptation period to the diets (1-2 weeks), pigs will be challenged with Salmonella enterica serovar Typhimurium resistant to nalidixic acid (10^4 CFU/pig). The start of fecal shedding of the bacteria will be monitored through individual fecal samples collected every 30 minutes for 6 hours. At 6 hours post-challenge, all pigs will be humanely euthanized and subjected to necropsy for sample collection (ileal contents, ileal tissue, mesenteric lymph node, cecal contents, and rectal contents). All samples will be analyzed for the frequency and levels of Salmonella to determine infection patterns. In the second experiment, a total of 40 pigs (divided in two replicates or blocks) will be used to compare two treatments (Control/No DDGS, and 30% DDGS inclusion in the diet). After an adaptation period to the diets (1-2 weeks), pigs will be challenged with Salmonella enterica serovar Typhimurium resistant to nalidixic acid (10^4 CFU/pig). Individual fecal samples will be collected every 48 hours to monitor the longitudinal frequency and levels of bacteria shedding (Salmonella and Escherichia coli) until 3 weeks post-challenge, when all pigs will be humanely euthanized and subjected to necropsy for sample collection (ileal contents, mesenteric lymph node, cecal contents, and rectal contents). Samples will be analyzed for the frequency and levels of Salmonella and Escherichia coli. Additionally, selected Escherichia coli isolates and intestinal content samples will be analyzed for antimicrobial resistance/susceptibility patterns and microbial diversity profiles, respectively.