2014 Naive Broiler CAFO Study for Agricultural Antibiotic Resistance in Mississippi State, Mississippi
Conventional commercial broiler production involves the rearing of more than 20,000 broilers in a single confined space, atop bedding material such as pine shavings or rice hulls, for approximately 6.5 weeks. This environment is known for harboring pathogens and antibiotic resistant bacteria, but studies have focused on previously established houses. A concerted effort by the broiler industry has involved the scaling back of antibiotic use on-farm, but this has only been a recent occurrence. In the current study, a set of three naïve houses were followed from inception through 11 broiler flocks and monitored for ambient climatic conditions, bacterial pathogens, and antibiotic resistance. Within the first 3 weeks of the first flock cycle, 100% of litter samples were positive for Salmonella and Listeria while Campylobacter was culture negative. In all likelihood, given that pre flock bedding and soil levels were negative for pathogens and 4-5 orders of magnitude lower for other indicators, chicks most likely provided the colonizing bacteria. The influence of intra-house location was minor with only watering lines and side walls influencing some pathogen and indicator levels. Most bacterial groups experienced the typical cyclical pattern of litter contamination seen in other studies. This study represents a first of its kind view into the time required for bacterial pathogens and antibiotic resistance to colonize and establish in naïve broiler houses.