Submitted to: United States Animal Health Association Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 11/8/2001
Publication Date: N/A
Technical Abstract: This report summarizes multiple research projects that have raised new possibilities for the control of Salmonella. The stressful effects of 18 hours lairage, mixing of groups, and fasting did not increase Salmonella isolation rates. This study suggests that stress is not the sole source of increased isolation rates after pigs leave the farm. Additionally, we identified 17 different Salmonella serotypes from pigs upon culturing tissues collected at slaughter; suggesting an extra-farm source of Salmonella. In another study, using six herds enrolled in the Accelerated Pseudorabies Eradication Program (APEP) market pigs (pen-mates) were randomly assigned to be necropsied either on the farm of origin or at the abattoir, after transport and holding. For abattoir necropsied pigs, the average Salmonella prevalence was five times (39.9%) higher than on-farm collected samples (5.3%) (p < 0.001). To determine if rapid infection, via oral exposure, was feasible in market weight swine, we conducted a controlled experiment. In this experiment, we demonstrated that market swine can become infected in the ileocecal lymph nodes and gastrointestinal tract after only 2 hours of exposure to Salmonella contaminated floor. In two, typical midwestern high- capacity pork processing plants (16,000 head/day); we isolated Salmonella from 100% of pens tested, and 83% of trucks. Twenty-five percent of samples from study pigs contained Salmonella serotypes found in the pens, but not found in the trucks.