** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** WITH THE GLOBAL POPULATION EXPECTED TO REACH 9.7 BILLION BY 2050, THE DEMAND FOR ANIMAL-BASED PROTEIN LIKE MEAT AND MILK IS INCREASING. THIS GROWTH POSES A CHALLENGE: HOW CAN FARMERS PRODUCE MORE FOOD WITHOUT HARMING THE ENVIRONMENT? LIVESTOCK, ESPECIALLY CATTLE, PRODUCE A SIGNIFICANT AMOUNT OF GREENHOUSE GASES (GHGS), MAINLY THROUGH METHANE EMISSIONS FROM THEIR DIGESTIVE SYSTEMS. THIS METHANE NOT ONLY CAN HARM THE PLANET BUT ALSO REPRESENTS A LOSS OF ABOUT 10% OF THE ENERGY COWS GET FROM THEIR FOOD. ADDITIONALLY, LIVESTOCK CAN POLLUTE WATER AND RELEASE OTHER HARMFUL GASES THROUGH MANURE MANAGEMENT. DESPITE EFFORTS, CURRENT STRATEGIES TO REDUCE THESE EMISSIONS HAVE SHOWN LIMITED SUCCESS WITHOUT AFFECTING THE ANIMALS' HEALTH AND PRODUCTIVITY. WE PROPOSE THAT A BETTER UNDERSTANDING OF THE MICROBES LIVING IN COWS' STOMACHS (RUMEN MICROBIOME) AND HOW THEY INTERACT WITH THE COWS' GENETICS AND DIET COULD BE THE KEY TO SOLVING THIS PROBLEM. OUR MAIN GOAL IS TO UNCOVER HOW THE RUMEN MICROBIOME AFFECTS METHANE PRODUCTION IN DAIRY COWS AND HOW DIET CHANGES CAN INFLUENCE THESE EMISSIONS. WE WILL FOCUS ON COWS WITH DIFFERENT GENETIC POTENTIALS FOR METHANE PRODUCTION TO INVESTIGATE IF DIET CAN MAKE A DIFFERENCE IN THEIR EMISSION LEVELS. WE ALSO AIM TO UNDERSTAND THE TRADE-OFFS INVOLVED IN REDUCING METHANE EMISSIONS AND THEIR IMPACT ON OTHER GREENHOUSE GASES PRODUCED FROM COW MANURE. FINALLY, WE WILL USE OUR FINDINGS TO DEVELOP EDUCATIONAL PROGRAMS AIMED AT PROMOTING ENVIRONMENTALLY FRIENDLY PRACTICES AMONG FARMERS AND THE BROADER COMMUNITY.BY THE END OF THIS RESEARCH, THE GOAL IS TO HAVE A CLEARER PICTURE OF HOW THE COW'S MICROBIOME INFLUENCES METHANE EMISSIONS. THIS KNOWLEDGE COULD LEAD TO THE DEVELOPMENT OF TARGETED FEEDING STRATEGIES AND BREEDING STRATEGIES THAT CONTRIBUTE TO LOWER METHANE EMISSIONS IN CATTLE, MAKING LIVESTOCK FARMING MORE SUSTAINABLE. WE ALSO ANTICIPATE THAT OUR FINDINGS WILL GUIDE THE DEVELOPMENT OF MORE EFFECTIVE WAYS TO MANAGE COW MANURE, REDUCING ITS ENVIRONMENTAL IMPACT. ULTIMATELY, THIS WORK WILL PROVIDE A FOUNDATION FOR FUTURE RESEARCH AND INNOVATION IN SUSTAINABLE LIVESTOCK PRODUCTION, GUIDING THE DEVELOPMENT OF MORE HOLISTIC AND EFFECTIVE APPROACHES TO REDUCE THE ENVIRONMENTAL IMPACT OF DAIRY FARMING.