**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** ERSISTENCE OF ANTIMICROBIAL RESISTANCE (AMR) IN LIVESTOCK POPULATIONS, FACILITIES AND SYSTEMS IS A CRITICAL CHALLENGE FOR U.S. PRODUCERS AND PUBLIC HEALTH. WHILE JUDICIOUS ANTIMICROBIAL USE MAY HELP TO DECREASE AMR IN THE LONG-TERM, NEW APPROACHES ARE NEEDED TO MITIGATE PERSISTENCE IN THE SHORT- AND MEDIUM-TERM. THIS IS ESPECIALLY TRUE FOR AMR MITIGATION AFTER ANTIBIOTIC EXPOSURES SUCH AS METAPHYLAXIS, WHICH ARE CRUCIAL FOR ANIMAL WELFARE.AMR DYNAMICS ARE DRIVEN BY MICROBIAL ECOLOGY AND EVOLUTION. THEREFORE, INTERVENTIONS THAT TARGET MICROBIOME RECOVERY AFTER ANTIBIOTIC EXPOSURE MAY HELP TO MITIGATE AMR DEVELOPMENT AND PERSISTENCE. TO TEST THIS HYPOTHESIS, WE PROPOSE A FIELD TRIAL TO INVESTIGATE THE IMPACTS OF POST-PROCESSING COMMINGLING AND A HIGH-FIBER POST-WEANING DIET ON AMR DYNAMICS AFTER METAPHYLAXIS IN SWINE. THROUGH MULTIVARIABLE MODELING AND NETWORK ANALYSIS OF TIME-SERIES METAGENOMIC DATA, WE WILL IDENTIFY WHEN AND HOW COMMINGLING AND DIET REDUCE AMR; AND WHICH MICROBIAL TAXA SIGNIFICANTLY ALTER AMR DYNAMICS.THESE RESULTS WILL GUIDE PRACTICAL AND EVIDENCE-BASED RECOMMENDATIONS FOR MANAGEMENT OF SWINE AFTER ANTIBIOTIC EXPOSURES; AND WILL PROVIDE A SPRINGBOARD FOR FURTHER MICROBIOME-BASED AMR MITIGATION STRATEGIES. TO HELP SUSTAIN THIS EFFORT, WE PROPOSE AN OPEN RESEARCH PORTAL WITH COMPANION TUTORIALS AND WORKSHOPS, WHICH WILL HELP TO REMOVE TECHNICAL BARRIERS AND PROMOTE INTEGRATION OF MULTI-OMIC DATA INTO EXISTING AMR RESEARCH PROGRAMS.