** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** INCREASED REPRODUCTIVE PERFORMANCE IN DAIRY CATTLE HAS ALLOWED FOR THE ADOPTION OF SEXED SEMEN BY DAIRY HERDS TO PROPAGATE SUPERIOR GENETICS. FROM 2019 TO 2021, INSEMINATIONS OF US HOLSTEINS WITH SEXED SEMEN INCREASED FROM 11.0 TO 17.7%. DESPITE INCREASED ADOPTION OF SEXED SEMEN INSEMINATIONS, THE IN VIVO FERTILITY OF SEXED SEMEN IS ~70 TO 80% RELATIVE TO CONVENTIONAL SEMEN. EMBRYOS DERIVED FROM SEXED SEMEN IN VITRO HAVE DELAYED DEVELOPMENT AND FEWER TRANSFERABLE EMBRYOS THAN CONVENTIONAL SEMEN. BEYOND OVERALL KINETICS AND FERTILITY, MINIMAL INFORMATION EXISTS ON HOW SEMEN PROCESSING AFFECTS EARLY EMBRYO DEVELOPMENT, IF THIS PERSISTS FOR TRANSFERABLE EMBRYOS IN VIVO, AND MANAGEMENT STRATEGIES TO MITIGATE EARLY PREGNANCY LOSS. THUS, THE LONG-TERM GOAL OF THIS INTEGRATED (RESEARCH AND EXTENSION) PROPOSAL IS TO UNDERSTAND HOW SEMEN PROCESSING AFFECTS SPERM CHARACTERISTICS AND EMBRYO DEVELOPMENT TO IMPROVE FERTILITY WITH SEXED SEMEN IN DAIRY HERDS. WE WILL USE IN VITRO AND IN VIVO EXPERIMENTS FOR OBJECTIVES 1 AND 2, RESPECTIVELY, TO ELUCIDATE HOW SEMEN PROCESSING AFFECTS SPERM CHARACTERISTICS AND PREIMPLANTATION EMBRYO DEVELOPMENT AND IN VIVO EMBRYO DEVELOPMENT AND ESTABLISHMENT OF PREGNANCY, RESPECTIVELY. IN OBJECTIVE 3, WE WILL DISSEMINATE THIS INFORMATION TO THE DAIRY INDUSTRY THROUGH A MULTIPLATFORM, HIGH-IMPACT EXTENSION PROGRAM. THIS PROPOSAL PROVIDES THE TECHNICAL AND PROFESSIONAL DEVELOPMENT TRAINING FOR THE PD DESIRES FOR THEIR CAREER ASPIRATIONS AS A PROFESSOR WITH A RESEARCH AND EXTENSION PROGRAM. THUS, THIS INTEGRATED PROPOSAL ALIGNS WITH THE PROGRAM AREA A7101- PREDOCTORAL FELLOWSHIP SPECIFICALLY FOR AFRI FARM BILL PRIORITY AREA 2. ANIMAL HEALTH AND PRODUCTION AND ANIMAL PRODUCTS.