**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** A SUBSTANTIAL PREGNANCY LOSS OCCURS IN CATTLE.PREGNANCIES FAIL TO REACH FULL-TERM BY 45-65% IN LACTATING DAIRY COWS, 10-30% IN SUCKLING BEEF COWS, AND 10-20% IN BEEF AND DAIRY HEIFERS WITH THE MAJORITY OF THESE OCCURRING PRIOR TO 60 DAYS OF PREGNANCY. MORE SPECIFICALLY, IN THE FIRST 8 TO 30 DAYS THESE PREGNANCIES HAVE A 20-40% FAILURE TO PROGRESS. THIS FAILURE TO PRODUCE A CALF HAS DETRIMENTAL EFFECTS ON PROFITABILITY FOR BOTH THE DAIRY AND BEEF INDUSTRIES WITH OVER $2 - $4 BILLION LOST IN TOTAL REVENUE OVER THE ENTIRE UNITED STATES. UNDERSTANDING FACTORS THAT LEAD TO THIS REPRODUCTIVE FAILURE WOULD GREATLY AID THE PRODUCTION OF THESE INDUSTRIES.IN VITRO PRODUCTION OF BOVINE EMBRYOS IS AN EXCELLENT METHOD TO STUDY THIS PREGNANCY FAILURE AND IMPROVE THE CATTLE INDUSTRY. IN VITROPRODUCTION OF EMBRYOS CONSISTSOF COLLECTING OOCYTESFOR MATURATION, FERTILIZATION, AND CULTURE. THERE ARE SEVERAL ADVANTAGES TO THIS TECHNOLOGY THAT INCLUDES THE OPPORTUNITY TO SELECT OOCYTES AND SEMEN FROM HIGH GENETIC MERIT ANIMALS THAT CAN BE CHOSEN FOR PRODUCTION TRAITS, HEALTH, LONGEVITY, AND DISEASE RESISTANCE. IVP TECHNOLOGY HAS HAD A 12% ANNUAL GROWTH RATE OVER THE PAST FEW DECADES. OVER ONE MILLION IVP EMBRYOS WERE PRODUCED WORLDWIDE IN 2019 WITH NORTH AMERICA REMAINING ONE OF THE LEADERS IN THIS TECHNOLOGY. WHILE THERE ARE SEVERAL ADVANTAGES, THERE ARE STILL UNRESOLVED ASPECTS OF IVP OF BOVINE EMBRYOS THAT LIMIT THE APPLICATION OF THIS TECHNOLOGY FOR PRODUCERS. ONE OF THESE LIMITING FACTORS IS THE FAILURE TO ADEQUATELY MIMIC THE IN VIVO ENVIRONMENT OF THE DAM. WHEN COMPARING EMBRYO PRODUCTION TO THE BLASTOCYST STAGE, ~35% OF IN VITRO DERIVED EMBRYOS REACH THIS STAGE OF DEVELOPMENT COMPARED TO MORE THAN 70% OF IN VIVO DERIVED EMBRYOS. ADDITIONALLY, ONLY 25% OF CATTLE THAT RECEIVE AND IVP EMBRYO WILL PRODUCE A LIVE CALF.THIS PROPOSAL WILL BE COMBATTING THIS HIGH INCIDENCE OF PREGNANCY FAILURE FOR IN VITRO PRODUCED EMBRYOS. IT WILL BE ACCOMPOLISHING THIS BY MODIFYING THE MEDIA IN WHICH EMBRYOS ARE CULTURED BY INCLUDING ANTIOXIDANTS AND DIFFERENT COMPOSITION. WE WILL BE ASSESSING THE IMPACTS THIS HAS BY ANALYZING EMBRYO DEVELOPMENT DURING CULTURE UP TO 8 DAYS. ADDITIONALLY, WE WILL ALSO PRODUCE EMBRYOS TO BE TRANSFERRED INTO THE COW TO EVALUATE EARLY FETAL DEVELOPMENT. THIS IS ESSENTIAL AS THERE HAVE BEEN REPORTED INCIDENCES OF LARGE OFFSPRING SYNDROME FROM IN VITRO PRODUCED EMBRYOS. BY DETERMINING THE IMPACT THIS MAY HAVE WITHIN THE PROPOSAL, WE WILL BE ABLE TO FULLY ASSESS THE APPLICATION THESE ALTERED MEDIA COMPONENTS HAVE FOR EMBRYO DEVELOPMENT AND USAGE WITHIN THE CATTLE INDUSTRY.