THE OVERALL OBJECTIVE OF THIS INTEGRATED RESEARCH PROPOSAL IS TO IDENTIFY GENOMIC MARKERS ASSOCIATED WITH EFFICIENT PLANT DECONSTRUCTION BY RUMEN MICROBIOME TO IMPROVE SELECTION FOR MILK PRODUCTION EFFICIENCY AND IMPROVE CURRENT PRACTICES ON THE GENETIC SELECTION OF DAIRY CATTLE. THE PROPOSED STUDIES WILL ADVANCE THE FIELD OF NUTRIENT UTILIZATION AND EFFICIENCY ADDRESSING THE IMPACT OF GASTROINTESTINAL MICROBIOME AND HOST GENETICS INFLUENCE ON MILK PRODUCTION EFFICIENCY. A DEEPER UNDERSTANDING OF THE GENETIC STRUCTURE ASSOCIATED WITH THE RUMEN MICROBIOME AND ITS MODULATION OF MILK PRODUCTION EFFICIENCY WILL BE IDENTIFIED CONTRIBUTING TO THE NEXT GENERATION OF GENOMIC MARKERS TO ADVANCE MILK PRODUCTION EFFICIENCY.