BETTER ANIMAL HEALTH AND DISEASE CONTROL HAS LEAD TO THE RISE IN ANTIBIOTIC USE AND IN TURN INCREASE IN AMR. ALTHOUGH STUDIES HAVE INVESTIGATED AMR GENES IN THE BEEF CATTLE PRODUCTION SYSTEM, THESE STUDIES HAVE YIELDED LIMITED SUCCESS IDENTIFYING THE ANTIMICROBIAL GENE RESERVOIRS AND ITS ECOLOGY, AS THESE STUDIES HAVE FAILED TO INVESTIGATE THE LARGEST RESERVOIR OF AMR GENES, THE PLASMIDOME, VIROME AND OTHER MOBILE GENETIC ELEMENTS WHICH ARE "HOTSPOTS" FOR "HORIZONTAL GENE TRANSFER EVENTS" AND AMR GENES. CONSEQUENTLY, THE OVERALL GOAL OF THIS APPLICATION IS TO DETERMINE THE ECOLOGY AND TRANSMISSION OF AMR GENE RESERVOIRS BY EVALUATING THE MOBILE GENETIC ELEMENTS IN THE CATTLE PRODUCTION SYSTEM AND DEVELOP SCIENCE-BASED INTERVENTION STRATEGIES TO MITIGATE EMERGENCE OF ANTIMICROBIAL DRUG RESISTANCE AND EFFECT CHANGE IN MANAGEMENT THROUGH OUTREACH. WE WILL UTILIZE A NEWLY RENOVATED RESEARCH FEEDLOT THAT HAS NOT BEEN EXPOSED TO ANY ANTIBIOTICS AND ANIMALS NEVER EXPOSED TO ANTIBIOTICS TO EVALUATE BASELINE LEVELS OF AMR GENES AND CHANGES AFTER ANTIBIOTIC EXPOSURE IN THE ANIMALS AND PEN SURFACE TO IDENTIFY AMR GENE PREVALENCE, ENRICHMENT, ECOLOGY AND TRANSMISSION. ADDITIONALLY, A NOVEL PROBIOTIC DEVELOPED BY THIS TEAM AGAINST LIVER ABSCESSES WILL BE EVALUATED. WE WILL PHENOTYPE THE VIROME, PLASMIDOME, MICROBIAL COMMUNITY AND ASSOCIATED AMR GENES, AND ANTIMICROBIAL COMPOUNDS. THIS WORK IS EXPECTED TO TRANSLATE TO THE DEVELOPMENT OF NOVEL MANAGEMENT AND NUTRITIONAL STRATEGIES THAT REDUCE ANTIMICROBIAL USE IN THE CATTLE PRODUCTION SYSTEM AND ESTABLISH A SUCCESSFUL OUTREACH NETWORK THAT YIELDS IMPROVED INFORMATION TRANSFER TO CONSUMERS TO INCREASE CONFIDENCE IN THE SAFETY OF BEEF PRODUCTS.