**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** FERTILITY IS THE LARGEST DRIVER OF PROFITABILITY IN THE ECONOMICALLY IMPORTANT BEEF INDUSTRY (BEEF MAKE UP 19% OF TOTAL FARM RECEIPTS AND 40% OF LIVESTOCK RECEIPTS) . BUT, HIGHLY ACCURATE TOOLS TO SELECT BEEF FEMALES (HEIFERS) THAT ARE MORE FERTILE HAVE NOT BEEN AVAILABLE. THE OVERALL GOAL OF THIS PROJECT IS TO IDENTIFY THE GENES AND DNA MARKERS REGULATING PUBERTY AND FERTILITY IN BEEF HEIFERS TO CREATE DNA TESTS. THE PROJECT HAS 4 OBJECTIVES:1. ESTIMATE AMOUNT OF VARIATION IN MEASURED TRAITS INFLUENCED BY DIFFERENT GENETIC EFFECTS (ADDITIVE, DOMINANCE, GENETIC INTERACTIONS)WE WILL ALSO MEASURE THE AMOUNT OF VARIATION DUE TO GENETICS SHARED BETWEEN TRAITS (GENETIC CORRELATION)2. IDENTIFY DNA MARKERS INFLUENCING PUBERTY AND FERTILITY FROM EXTENSIVE ANALYSES OF DATA FROM INDIVIDUAL BREEDS3. COMBINE INFORMATION ACROSS BREEDS, TRAITS, AND DATA SETS TO IDENTIFY GENE NETWORKS, GENES, AND VARIANTS THAT INFLUENCE PUBERTY AND FERTILITY4. FOCUSING ON KNOWLEDGE LEARNED IN OBJECTIVES 2 &AMP; 3, CONTRAST SINGLE-TRAIT VERSUS MULTIPLE-TRAIT DNA PREDICTIONS FOR PUBERTY AND FERTILITYWE EXPECT THAT WE WILL BETTER UNDERSTAND WHICH GENES CONTROL DIFFERENCES IN PUBERTY AND FERTILITY. BEEF FARMERS AND RANCHERS WILL HAVE NEW DNA TESTS TO SELECT MORE FERTILE HEIFERS, WHICH WILL INCREASE BEEF SUSTAINABILITY.