**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** INADEQUATE MATERNAL NUTRITION DURING GESTATION IMPAIRS FETAL GROWTH AND METABOLISM, LEADING TO REDUCED PRODUCTIVITY AND QUALITY OF ANIMAL PRODUCTS. THE LIVER, A KEY METABOLIC ORGAN, IS NEGATIVELY AFFECTED BY POOR MATERNAL NUTRITION THROUGH ALTERED METABOLISM. CHANGES IN THE EPIGENETIC PROFILE IN THE LIVER OF OFFSPRING DUE TO MATERNAL DIET ARE LIKELY MAJOR CONTRIBUTORS TO LIFELONG METABOLIC DYSREGULATION. BETAINE PROMOTES GROWTH, IMPROVES METABOLISM, AND IS IMPORTANT IN EPIGENETIC REGULATION AS A METHYL DONOR. WE HYPOTHESIZE THAT 1) MATERNAL NUTRIENT RESTRICTION IMPAIRS GROWTH AND METABOLISM OF OFFSPRING THROUGH EPIGENETIC REGULATION OF GENES INVOLVED IN GROWTH AND METABOLISM IN THE LIVER AND 2) BETAINE SUPPLEMENTATION DURING GESTATION WILL ALLEVIATE THESE NEGATIVE EFFECTS. TO TEST OUR HYPOTHESES, WE WILL USE OUR WELL-ESTABLISHED SHEEP MODEL OF POOR MATERNAL NUTRITION (100% AND 60%, RESPECTIVELY, OF NUTRIENT REQUIREMENTS) WITH AND WITHOUT BETAINE SUPPLEMENTATION DURING GESTATION AND COLLECT FETUSES AT DAY 130 OF GESTATION. AT THIS TIME, WE WILL CAPTURE CHANGES IN EPIGENETIC REGULATION IN THE LIVER, LIVER FUNCTION, MUSCLE GROWTH (A KEY PRODUCT), AND GROWTH AND METABOLIC FACTORS. WE ANTICIPATE IDENTIFICATION OF ALTERED GENE EXPRESSION, METHYLATION, AND HISTONE MODIFICATIONS IN OFFSPRING LIVERS BASED ON THE MATERNAL GESTATIONAL DIET. ADDITIONALLY, BETAINE SUPPLEMENTATION WILL ALLEVIATE SOME OF THESE CHANGES, IMPROVING LIVER FUNCTION, OVERALL METABOLISM, AND MUSCLE GROWTH. THROUGH THE ANIMAL HEALTH AND PRODUCTION AND ANIMAL PRODUCTS PRIORITY AREA ANIMAL NUTRITION, GROWTH AND LACTATION, WE ARE COMMITTED TO ADDRESSING USDA AFRI PROGRAM PRIORITY AREAS OF METABOLIC DISORDERS AND NUTRITIONAL DEFICIENCIES WHILE IMPROVING THE QUALITY AND EFFICIENCY OF PRODUCTION.