**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** OUR RESEARCH HAS DEMONSTRATED THAT ARGININE, EITHER MADE IN THE BODY OR PROVIDED AS A DIETARY SUPPLEMENT IS REQUIRED FOR PRODUCTION OF NITRIC OXIDE AND POLYAMINES THAT ARE ESSENTIAL FOR GROWTH, DEVELOPMENT AND SURVIVAL OF CONCEPTUSES (EMBRYO/FETUS AND PLACENTA). FURTHER, DIETARY SUPPLEMENTATION OF DIETS OF PIGS, RODENTS AND HUMANS ENHANCES GROWTH AND DEVELOPMENT OF CONCEPTUSES IN THOSE SPECIES. WE ALSO KNOW THAT ARGININE AND GLYCINE ARE REQUIRED FOR SYNTHESIS OF ANOTHER CLASS OF METABOLITES IN THE BODY KNOWN AS CREATINE AND PHOSPHOCREATINE (PCR) THAT YIELD HIGH AMOUNTS OF ENERGY IN THE FORM OF ADENOSINE TRIPHOSPHATE (ATP) IN CELLS OF CONCEPTUSES. ATP IS REQUIRED FOR ALL ENERGY-DEPENDENT ACTIVITIES IN BIOLOGICALLY ACTIVE CELLS. DEVELOPMENT OF THE CONCEPTUSES IN ALL MAMMALS REQUIRES THAT THEIR CELLS ACTIVELY DIVIDE, MIGRATE AND DIFFERENTIATE TO ALLOW FOR ELONGATION OF THE TROPHECTODERM (TR) REQUIRED FOR ATTACHMENT OF THE CONCEPTUS TO THE UTERINE WALL AND THEN FORMATION OF THE PLACENTA REQUIRED FOR THE EXCHANGE OF NUTRIENTS AND GASES (OXYGEN AND CARBON DIOXIDE) BETWEEN MOTHER AND CONCEPTUS. ALL OF THOSE EVENTS INVOLVE ATP-DEPENDENT EVENTS INCLUDING CELL DIVISION, CELL MIGRATION, AND CYTOSKELETAL CHANGES THAT REQUIRE A RAPID RATE OF ENERGY TURNOVER. THE GOAL OF THIS RESEARCH IS UNDERSTAND THE METABOLIC PATHWAY WHEREBY CELLS OF THE CONCEPTUS SYNTHESIS CREATINE AND ATP, BUT ALSO TO DETERMINE IF DIETARY SUPPLEMENTATION WITH SPECIFIC NUTRIENTS CAN ENHANCE GROWTH, DEVELOPMENT AND SURVIVAL OF FETUSES AND NEONATES. FOR PIGS, AS NONRUMINANTS, WE SUPPLEMENT THE DIET OF PREGNANT GILTS TO DETERMINE IF THAT INCREASES SURVIVAL OF CONCEPTUSES, BUT ALSO THE NUMBER OF MUSCLE FIBERS TO ULTIMATELY INCREASE CARCASS YIELDS OF PORK. FOR RUMINANTS, CREATINE WOLJUDL BE BROKEN DOWN IN THE RUMEN, SO WE WILL NEED TO BE MORE CREATIVE IN SUPPLEMENTING THE DIET WITH CITRULLINE THAT IS CONVERTED RAPIDLY TO ARGININE IN THE BODY AND USED TO INCREASE PRODUCTION OF CREATINE THROUGH COOPERATION IN METABOLISM BETWEEN THE KIDNEY AND LIVER. THE ULTIMATE GOAL IT TO BE ABLE TO RECOMMEND TO LIVESTOCK PRODUCERS A STRATEGY TO INCREASE AVAILABLE CREATINE TO CONCEPTUSES THROUGH DIETARY SUPPLEMENTATION WITH CREATINE FOR NONRUMINANTS AND CITRULLINE FOR RUMINANTS AND INCREASE THEIR ECONOMIC RETURNS FROM THEIR LIVESTOCK OPERATION.