Management and environmental factors influence the prevalence and abundance of food-borne pathogens and commensal bacteria in peanut hull-based broiler litter

Authors: Oladeinde, Adelumola - Ade; BABAFELA, AWOSILE - Texas Tech University; WOYDA, REED - Colorado State University; ABDO, ZAID - Colorado State University; ENDALE, DINKU - Former ARS Employee; STRICKLAND, TIMOTHY - US Department Of Agriculture (USDA); Plumblee Lawrence, Jodie; Cudnik, Denice; House, Sandra; Cook, Kimberly - Kim

Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/1/2022
Publication Date: 12/8/2022
Citation: Oladeinde, A., Babafela, A., Woyda, R., Abdo, Z., Endale, D., Strickland, T., Plumblee Lawrence, J.R., Cudnik, D., House, S.L., Cook, K.L. 2022. Management and environmental factors influence the prevalence and abundance of food-borne pathogens and commensal bacteria in peanut hull-based broiler litter. Poultry Science. https://doi.org/10.1016/j.psj.2022.102313.
DOI: https://doi.org/10.1016/j.psj.2022.102313

Interpretive Summary: In the United States, it is a common practice to reuse the same litter for raising multiple flocks of chickens. Although the practice of litter reuse offers fiscal and environmental benefits, litter can harbor food-borne pathogens like Salmonella and Campylobacter. The pecking and coprophagic behavior of chickens makes the litter one of the first broiler sourced material ingested after chick placement. Therefore, litter is a major route for chickens to get exposed to bacterial pathogens. Understanding broiler management and environmental factors that could be used to predict the occurrence of food-borne pathogens in reused litter is vital to limiting their prevalence in post-harvest chicken production. In this study, we sought to investigate the pathogenic (Salmonella and Campylobacter) and indicator/commensal (E. coli, Enterococcus spp. and Staphylococcus spp.) bacterial populations in peanut hull-based litter from four broiler houses over three consecutive flocks, starting with a complete house cleanout and fresh peanut hull application. We found that number of flocks raised on litter, age of chickens, broiler house and litter pH were the main management and environmental factors associated with the prevalence of Salmonella and/or Campylobacter in litter.

Technical Abstract: In this study, we conducted a longitudinal sampling of peanut hull-based litter from a farm under a “no antibiotics ever” program. Our objective was to determine broiler management practices and environmental factors that are associated with the occurrence of food-borne pathogens (Salmonella and Campylobacter) and the abundance of commensal bacteria (Escherichia coli, Enterococcus spp. and Staphylococcus spp.). Litter (n =288) was collected from four broiler houses over three consecutive flocks, starting with a complete house cleanout and fresh peanut hull. Litter was sampled at the beginning of each grow-out cycle and at the end of the cycle. Logistic and linear regression models were used to model the relationships between pathogen prevalence, commensal abundance and management practices and environmental factors. The number of flocks raised on litter, grow-out period, broiler house, litter pH, litter moisture and house temperature were associated with the prevalence of pathogens and the abundance of commensal bacteria in litter. The final logistic model for pathogens showed that a higher probability of detecting Salmonella in litter was associated with the number of flocks raised on litter and the grow-out period. A higher probability of detecting Campylobacter in litter was associated with the number of flocks raised on litter, broiler house and the sections of the house, and the pH of litter. Our results suggest that management practices and environmental factors affect Salmonella and Campylobacter differently and suggest that each pathogen will require its own tailored intervention to stop their persistence in broiler litter.