** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** TODAY, COWS AREN'T GETTING PREGNANT AS EASILY AS BEFORE, LEADING TO ISSUES LIKE REDUCED MILK PRODUCTION, SMALLER HERDS, INCREASED REPRODUCTIVE COSTS, AND SOMETIMES THE NEED TO CULL ANIMALS. WHILE GENETICS PLAYS A MODERATE ROLE IN COW FERTILITY, ENHANCING THE GENETIC ASPECT OF REPRODUCTION COULD BE COST-EFFECTIVE AND MORE SUSTAINABLE IN THE LONG TERM. THE OVERALL GOAL OF THIS PROJECT IS TO IDENTIFY THE GENES AND MUTATIONS ASSOCIATED WITH COW FERTILITY AND UTILIZE THIS KNOWLEDGE TO ENHANCE THEIR REPRODUCTIVE SUCCESS. THE SPECIFIC AIMS ARE TO: 1) CONDUCT A LARGE-SCALE STUDY INVOLVING MILLIONS OF COWS TO IDENTIFY CANDIDATE GENES LINKED TO FERTILITY, 2) IDENTIFY THE GENETIC VARIATIONS INFLUENCING FERTILITY BY ANALYZING FUNCTIONAL GENOMICS DATA, AND 3) SELECT A GROUP OF FERTILITY-RELATED VARIANTS TO AID IN ANIMAL BREEDING DECISIONS. THIS PROJECT REPRESENTS THE LARGEST STUDY OF CATTLE FERTILITY TO DATE AND IS EXPECTED TO SIGNIFICANTLY IMPACT DAIRY PROFITABILITY AND ANIMAL WELFARE. BY UTILIZING THE US DAIRY GENOMICS DATABASE, THIS INVESTIGATION WILL DEEPEN OUR UNDERSTANDING OF CATTLE REPRODUCTION GENETICS AND ASSIST IN THE SELECTION OF SUPERIOR COWS.