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. 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 NUTRIENTS CONSUMED BY BEEF HEIFERS DURING EARLY GESTATION CAN IMPACT OFFSPRING LIVER AND MUSCLE; TWO KEY TISSUES THAT INFLUENCE FEED EFFICIENCY. 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 MATERNAL PLANE OF NUTRITION DURING EARLY 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 AN ENERGY SUPPLEMENT TO BEEF HEIFERS DURING THE FIRST 84 DAYS OF GESTATION ON OFFSPRING GROWTH AND PERFORMANCE, AND ON GENE EXPRESSION IN LIVER AND MUSCLE OF THE F1 AND F2 GENERATIONS. WE EXPECT TO OBSERVE ENHANCED PERFORMANCE AND ALTERED GENE EXPRESSION IN THE F1 GENERATIONS AND ALTERED GENE EXPRESSION IN LIVER AND MUSCLE OF THE F2 GENERATION DUE TO ENHANCED MATERNAL NUTRITION. THESE CHANGES WILL SOLIDIFY THE IMPORTANCE OF MATERNAL NUTRITION DURING EARLY 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 PROJECT 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.