FEED-RELATED COSTS ARE THE LARGEST DIRECT EXPENSES INCURRED BY BEEF PRODUCERS. STRATEGIES THAT OPTIMIZE EFFICIENCY OF CONVERTING FEED INTO ENERGY FOR GROWTH AND REPRODUCTION, THEREFORE, ARE INTIMATELY RELATED TO PROFITABILITY. THOUGH SUPPLEMENTATION OF VITAMINS AND TRACE MINERALS TO REPRODUCING FEMALES CAN PLAY IMPORTANT ROLE IN GROWTH AND REPRODUCTIVE PERFORMANCE, PRODUCER DECISIONS ABOUT WHETHER TO PROVIDE SUPPLEMENTS VARY WIDELY. DEVELOPMENTAL PROGRAMMING IS A TERM USED TO DESCRIBE THE EFFECTS OF THE ENVIRONMENT EXPERIENCED BY A FEMALE DURING GESTATION ON THE OFFSPRING SHE IS CARRYING. OUR RESEARCH GROUP HAS DEMONSTRATED THAT PROVIDING VITAMIN AND MINERAL SUPPLEMENTS TO BEEF HEIFERS DURING GESTATION CAN IMPACT LIVER AND INTESTINE CHARACTERISTICS AT BIRTH, WHICH COULD LEAD TO MORE POST-NATAL IMPACTS ON GROWTH AND METABOLISM OF FEED CONSUMED. INTERESTINGLY, AT THE SAME A GESTATING FEMALE FETUS (F1 GENERATION) IS BEING INFLUENCED BY THE ENVIRONMENT HER DAM IS EXPERIENCING, HER OWN GERM CELLS (I.E. FUTURE F2 GENERATION OFFSPRING) ARE DEVELOPING. WE HYPOTHESIZE THAT PROVIDING VITAMIN AND MINERAL SUPPLEMENT DURING GESTATION WILL DEVELOPMENTALLY PROGRAM HER F1 OFFSPRING, AND ALSO HAVE EFFECTS THAT EXTEND MULTIGENERATIONALLY TO THE F2 GENERATION. OUR SPECIFIC OBJECTIVES ARE TO ASSESS THE IMPACTS OF PROVIDING VITAMIN AND MINERAL SUPPLEMENT TO BEEF HEIFERS THROUGHOUT GESTATION, COMPARED TO UNSUPPLEMENTED HEIFERS ON: 1) ABUNDANCE OF PLACENTAL TRANSCRIPTS RELATED TO MINERAL TRANSPORT, ACCUMULATION OF MINERAL IN KEY TISSUES OF METABOLISM, ORGAN DEVELOPMENT, BONE MINERAL DENSITY, AND HORMONES AND METABOLITES AT BIRTH IN F1 CALVES; 2) POSTNATAL GROWTH AND PERFORMANCE, HORMONE, AND METABOLITES IN F1 HEIFER OFFSPRING; AND 3) ENERGY METABOLISM OF F1HEIFERS AND F2 FETUSES. WE EXPECT TO OBSERVE ENHANCED OFFSPRING GROWTH, INCREASED RETAINED ENERGY AND ALTERED GENE EXPRESSION IN THE F1 GENERATION, AND ALTERED GENE EXPRESSION AND CELLULAR ENERGY METABOLISM IN THE F2 GENERATION DUE TO MATERNAL VITAMIN AND MINERAL SUPPLEMENTATION. THESE CHANGES WILL SOLIDIFY THE IMPORTANCE OF MATERNAL VITAMIN AND MINERAL NUTRITION DURING GESTATION AND HIGHLIGHT THE IMPACTS OF MATERNAL NUTRITION NOT ONLY ON THE OFFSPRING BEING GESTATED, BUT ALSO THE MULTIGENERATIONAL IMPACTS THAT ARE BEING IMPOSED ON THE F2 GENERATION. THIS PROTOCOL IS AN IMPORTANT STEP TOWARD DEVELOPING TARGETED FEEDING STRATEGIES DURING EARLY GESTATION THAT COULD BE IMPLEMENTED BY BEEF PRODUCERS THAT HARNESS THE POWER OF DEVELOPMENTAL PROGRAMMING ACROSS GENERATIONS TO POSITIVELY INFLUENCE THE LONG-TERM PRODUCTIVITY AND PROFITABILITY OF THEIR HERDS.