Walter, Audrey2019-02-122019-02-122018-08https://hdl.handle.net/11299/201722University of Minnesota M.S. thesis. August 2018. Major: Animal Sciences. Advisor: Gerald Shurson. 1 computer file (PDF); ix, 251 pages.The objective of this thesis was to provide information to the U.S. ethanol industry, and global feed, livestock, and poultry industries of the prevalence and concentration of antibiotic residues in DDGS, the potential for selected Lactobacilli sp. to develop resistance to penicillin G and virginiamycin (VM), and the use of thermal degradation kinetics and process modeling to determine the risk of VM residues in animal-derived food products. Survey results suggest that it is unlikely for penicillin and VM residues to be detected in DDGS if ethanol producers are following GRAS approved dosing of these antibiotics, and VM reduces the risk of Lactobacilli sp. from acquiring antibiotic resistance during ethanol production. The exposure assessment showed that concentrations of VM M1 subunit is not greater than maximum residue limit (MRL) in pork and chicken when feeding DDGS at maximum diet inclusion rates and including conservative inputs in the model.enantibiotic resistancedried distillers grains with solubles (DDGS)ICM designed fuel ethanol productionquantitative exposure assessmentsurvey of the current DDGS marketvirginiamycin thermal degradation kineticsThesis or Dissertation