|Richert, Brian -|
|Lay, Jr, Donald|
Submitted to: Rowett Research Institute Institute National De La Resherche Agronomique Joint Symposium
Publication Type: Abstract Only
Publication Acceptance Date: May 10, 2012
Publication Date: June 17, 2012
Citation: Rostagno, M.H., Richert, B.T., Lay Jr, D.C. 2012. Effect of stress on Salmonella, coliforms and lactobacilli in different portions of the intestinal tract of swine. Rowett Research Institute Institute National De La Resherche Agronomique Joint Symposium. Proceedings. Technical Abstract: Farm animals are exposed to a variety of stressors during their lives. However, very little is known about the effect of stress on intestinal microbial populations. Therefore, two experiments were conducted to investigate the effect of common stressors (feed withdrawal, transportation, and lairage) on frequency of Salmonella shedding, as well as on levels of Salmonella, coliforms and lactobacilli in swine. In the first study, significant increase (P<0.05) of Salmonella shedding frequency was observed in pigs subjected to transportation, and additional increase (P<0.05) occurred in pigs subjected to lairage. No effects were observed on fecal levels of total coliforms or total lactobacilli. However, a significant increase of the fecal levels of ampicillin-resistant lactobacilli was caused by transportation and lairage (P<0.05). In the second study, feed withdrawal by itself or combined with transportation caused increased levels of Salmonella in the ileum (P<0.05), whereas only both stressors combined caused increased levels of Salmonella in the cecum (P<0.05). Fecal levels of Salmonella were not affected by any of the stressors, individually or combined. While ileal levels of total coliforms were not affected by feed withdrawal and/or transportation, total ileal lactobacilli, as well as its subpopulations resistant to tetracycline and erythromycin decreased (P<0.05) in response to the combined stressors. No effects of the investigated stressors were observed in any of the cecal coliform or lactobacilli populations analyzed. These studies demonstrate that stress does affect intestinal microbial populations in pigs with Salmonella and lactobacilli being more susceptible to the effects of stressors compared to total coliforms. Moreover, it was revealed that interactions between type/intensity of stress, region of the intestinal tract, and type of microbial population exist. Studies of the effects of stress on intestinal microbial populations are scarce, and therefore, a critical need exists for further investigation.