Animal Science, Department of
Nebraska Beef Cattle Reports
Date of this Version
2022
Abstract
The objective of this study was to evaluate the effectiveness of lime amendment on the reduction of antimicrobial resistant bacteria and antimicrobial resistance genes in beef cattle manure in open feedlots. Hydrated lime was uniformly applied to the surface of feedlot pen floor 1 day prior to cattle harvest at a rate of 0.36 lb/ft2 and samples were collected over time. Collected samples were analyzed for change in pH and levels of antimicrobial resistant bacteria and antimicrobial resistance genes. Lime amendment elevated the pH of pen floor surface materials to pH > 12 for 4 hours and then pH > 11 for another 24 hours. Lime amendment reduced the concentration of generic and resistant Escherichia coli by 1–2 log for up to 4 hours. The abundance of antimicrobial resistance genes, such as tet(X) and tet(O), decreased by 1–2 order of magnitude with lime amendment. Results indicate that lime addition reduced the concentrations of antimicrobial resistant bacteria and antimicrobial resistance genes in pen surface materials from open beef feedlot pens.
Included in
Large or Food Animal and Equine Medicine Commons, Meat Science Commons, Veterinary Preventive Medicine, Epidemiology, and Public Health Commons