Thermal Risk for Salmonella in Swine

NON-TECHNICAL SUMMARY: In spite of the widely acknowledged value to food safety and public health of controlling Salmonella in live food animals, there has been little progress in identifying cost-effective interventions for Salmonella pre-harvest. Of the potential interventions that have shown evidence of consistent effects, they predominantly require the farmer to incur costs without identifiable economic incentive. Improved management of ventilation in barns is expected to not only reduce Salmonella risk, but also improve the health and growth of pigs. This has implications not only for food safety, but also the economic return for producers and the health and welfare of swine.

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APPROACH: Our Approach is outlined for each of the individual objectives: <P>Objective 1: Describe the thermal environment during the finishing phase The need addressed in this objective is a longitudinal detailed description of ventilation/environmental performance in producer owned and managed finisher barns. The approach is to continuously monitor growing swine thermal environment (temperature, relative humidity, temperature/humidity index (THI) and temperature variability), with the use of electronic data loggers. <P>Objective 2: Establish the association between thermal parameters and Salmonella prevalence The working hypothesis is that thermal parameters in the pig environment will be associated with Salmonella prevalence in finisher swine. The approach is a longitudinal cohort study evaluating the association between the thermal environment of barns (temperature, relative humidity, temperature/humidity index (THI) and temperature variability) and the prevalence of Salmonella shedding in finisher swine. <P>Objective 3: Evaluate the association between thermal parameters and pathogen load. The working hypothesis is that thermal parameters in the pig environment will be associated with the fecal concentration of Salmonella shed by finisher swine. The approach is a longitudinal cohort study evaluating the association between the thermal environment of barns (temperature, relative humidity and temperature/humidity index (THI) temperature variability) and fecal concentration of Salmonella determined by Real-time Quantitative PCR. <P>To the best of our knowledge, this represents the first epidemiological study of the impact of the thermal environment on Salmonella prevalence and pathogen load in swine. At the completion of these studies our expectation is that we will have established the association between Salmonella fecal prevalence and pathogen load in swine with thermal parameters of the swine building environment. This will have significant positive effects on the reduction of Salmonella prevalence pre-harvest and the continued success and sustainability of US agriculture as it will allow for identification of production performance improving interventions for more optimal management of swine farm ventilation/housing and may provide for a non-microbiological pre-harvest method to identify groups of swine at risk for high Salmonella prevalence and high concentrations of fecal shedding of Salmonella at the time of harvest.