Submitted to: Foodborne Pathogens and Disease
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/27/2006
Publication Date: 4/1/2007
Citation: Dowd, S.E., Callaway, T.R., Morrow, J.L. 2007. Handling may cause increased shedding of Escherichia coli and total coliforms in pigs. Foodborne Pathogens and Disease. 4(1):99-102. Interpretive Summary: Many normal activities on farms, such as moving animals from one pen to another, may cause mild stress to the animal. Farmers seek to reduce the level of stress on animals so the animals stay healthier. Often when animals are stressed, they might be more likely to develop illnesses. To evaluate if mild to moderate stress would affect indicator populations of bacteria shed in the pigs feces, we utilized a common management practice of moving pigs from one pen to another and back again. It was found that pigs that were moved around daily shed higher levels of indicator populations including Escherichia coli and coliform bacteria. The results indicate that these two bacterial populations may serve as easy to measure noninvasive indicators of mild stress in pigs.
Technical Abstract: Many common management practices such as transportation, weaning, handling, and the formation of new groups of animals are stressful to food animals. Stress affects the ability of the immune system to combat infectious disease; however, the effects of stress on the intestinal microbial ecosystem are unknown. This study was designed to evaluate the effect of a minor form of handling stress on intestinal populations of E. coli and coliforms in swine. Finishing pigs were subjected to a minor handling stress in which they were removed from their pens each day, moved down an alley to a scale, weighed individually, and moved back to their pens. This procedure was done with the control groups once at the beginning and at the end of the study, while treatment groups were weighed each day for 8 days. Most probable numbers (MPN) of Escherichia coli and coliforms were measured for treatment and control groups. An increased MPN (p < 0.001) for E. coli and coliforms was seen in the treatment groups compared to the control groups. Female pigs showed a greater increase in MPN levels than males for both E. coli and coliforms during the course of study (p < 0.05). These data indicate that handling stress may affect fecal shedding of enterobacteriacea, female pigs may shed more coliforms and E. coli in response to handling stress, and E. coli and coliforms MPN may provide a good non-invasive indicator of stress in pigs.