Discipline: Biological Sciences
Diana Zamora - Kansas State University
Co-Author(s): Anne Huss, Kansas State University, Manhattan, KS
Salmonella has been identified as a significant biological hazard in animal feed ingredients and animal feed. Salmonella can cause salmonellosis when the pathogen is consumed by humans. Salmonella-contaminated animal feed can use illness in animals that consume the feed, but only particular serovars are pathogenic to animal health. Salmonella Enteritidis (SE) is recognized as one of the serovars that is pathogenic to poultry. SE was the cause of a large scale shell-egg recall in 2010 that resulted in 1,939 human illnesses in 11 states. Poultry feed has been shown to be contaminated with SE due to cross-contamination of contaminated ingredients. A dry powder acidulant, sodium bisulfate (SBS), has both acidulant and desiccant properties that may mitigate Salmonella growth in animal feed over time. The inclusion of a dry powder acidulant at increasing concentrations will result in decreasing the presence of Salmonella over time in a poultry diet. SBS was added to poultry mash followed by artificial inoculation with Salmonella enterica subsp. enterica serovar Enteritidis. SBS was added at inclusion levels of 0.0, 0.25, 0.50, and 0.70%. Enumeration of Salmonella was carried out on day 0, 1, 2 and 7 post-inoculation using a standard plate count method and spreading to Xylose Lysine Deoxycholate (XLD) agar. Results from plate counts were analyzed using the GLIMMIX procedure of SAS with dry powder acidulant concentration as a fixed effect and enumeration date serving as a repeated measure. Orthogonal contrasts were used to evaluate the linear effect of increasing dry powder acidulant concentration of time on resultant SE level. There was no interaction between dry powder acidulant concentration and time on resultant Salmonella levels. There was a tendency of Salmonella levels to decrease linearly with increasing dry powder acidulant concentration, with the highest tested inclusion level (0.70%) resulting in an average 0.55-log reduction. Salmonella concentrations decreased linearly over time in all treatments, with an average 4.92-log reduction between d 0 and 7. Potentially, higher levels of the dry acidulant may result in further linearity improvements in Salmonella mitigation. Changes in diet formulation may result in varying mitigation, which must be further evaluated. Also, changes in the pH vs. desiccant action should be quantified to determine if similar improvements can be over served using lower-cost feed acidulant.
Funder Acknowledgement(s): USDA National Institute of Food and Agricultural.
Faculty Advisor: Cassandra Jones,