**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** THIS PROJECT SUPPORTS THE MISSION OF THE AGRICULTURAL EXPERIMENT STATION BY ADDRESSING THE HATCH ACT AREA(S) OF: PLANT AND ANIMAL PRODUCTION, PROTECTION, AND HEALTH; SUSTAINABLE AGRICULTURE; MOLECULAR BIOLOGY; BIOTECHNOLOGY.THE US POULTRY INDUSTRY IS THE LARGEST POULTRY MEAT PRODUCER IN THE WORLD. GENETIC IMPROVEMENT IN GROWTH-RELATED TRAITS HAS ENABLED THE INDUSTRY TO MEET INCREASING CONSUMER DEMAND. IDENTIFYING CASUAL VARIANTS UNDERLYING THESE LARGE GENETIC GAINS WILL IMPROVE GENOMIC SELECTION FOR IMPORTANT AGRONOMIC TRAITS. OUR CENTRAL HYPOTHESIS IS THAT VARIATION IN GENE EXPRESSION ARE THE MAJOR DRIVER FOR PHENOTYPIC VARIATION, THUS, CAUSATIVE VARIANTS IN EXPRESSED QUANTITATIVE TRAIT LOCI IN BIOLOGICALLY RELEVANT TISSUES ARE THE MAJOR CONTRIBUTING MECHANISM FOR HIGHER GROWTH RATE IN CHICKENS. THIS PROJECT IS TO IDENTIFY CANDIDATE CAUSATIVE VARIANTS ASSOCIATED WITH BREAST MUSCLE YIELD AND GROWTH RATE BY UTILIZING AN ADVANCED INTERCROSS CHICKEN POPULATION DERIVED FROM MODERN BROILERCROSSED BY A RESILIENT CHICKEN LINE USING THE CUTTING-EDGE GENETIC AND GENOMIC ASSAYS. IF SUCCESSFUL, THE POTENTIAL CAUSATIVE POLYMORPHISMS IDENTIFIED FOR THEM WILL IMPROVE PRECISION GENOME SELECTION AND ENHANCE OUR BIOLOGICAL UNDERSTANDING OF KEY GENOME ELEMENTS THAT WILL TRANSLATE INTO SIGNIFICANT IMPROVEMENTS FOR US POULTRY BREEDERS AND PRODUCERS AND ULTIMATELY US CONSUMERS. FINALLY, MORE EFFICIENT ANIMALS WILL HAVE LESS OF AN ENVIRONMENTAL IMPACT, AN ISSUE OF GROWING URGENCY DUE TO CHANGES IN CLIMATE AND POPULATION GROWTH.