IT IS KNOWN THAT NUTRITION OF PREGNANT COWS AND HEIFERS HAS LONG-TERM EFFECTS ON CALVES, INCLUDING DECREASED HEALTH AND PRODUCTION OF CALVES WHEN COWS DO NOT RECEIVE ADEQUATE NUTRITION DURING DROUGHT OR POOR FORAGE PRODUCTION. DESPITE THIS, WE KNOW SURPRISINGLY LITTLE ABOUT WHAT DRIVES THESE CHANGES, WHICH MAKES IT DIFFICULT TO SUGGEST IMPROVED MANAGEMENT OF PREGNANT COWS. IT IS OUR HYPOTHESIS THAT POOR NUTRITION DURING LATE PREGNANCY OF BEEF CATTLE HARMS DEVELOPMENT OF CALVES BY REDUCING NUTRIENTS DELIVERED TO THE FETUS, AND THEN DECREASES NUTRIENTS DELIVERED TO THE CALF THROUGH REDUCED MILK PRODUCTION AND POOR ABILITY OF THE SMALL INTESTINE TO BRING IN NUTRIENTS. OUR OBJECTIVE IS TO DETERMINE EFFECTS OF POOR NUTRITION DURING LATE PREGNANCY ON NUTRIENT DELIVERY AND USE BY CALVES BEFORE AND AFTER BIRTH. IN THIS PROJECT, WE WILL FEED PREGNANT HEIFERS EITHER 100% OF NUTRIENT RECOMMENDATIONS, 70% OF THESE RECOMMENDATIONS DURING THE LAST 120 DAYS OF PREGNANCY. NUTRIENT DELIVERY TO THE FETUS WILL BE MEASURED THROUGH MATERNAL NUTRIENTS IN THE BLOOD, UTERINE BLOOD FLOW, GROWTH AND DEVELOPMENT, AND NEWBORN CALF METABOLIC STATE AND VIGOR. NUTRIENT DELIVERY TO THE CALF AFTER BIRTH WILL BE MEASURED THROUGH COLOSTRUM AND MILK YIELD, CALF SMALL INTESTINAL TRANSPORT CAPACITY, AND LONG-TERM CALF GROWTH. THIS RESEARCH WILL BOTH INCREASE OUR UNDERSTANDING OF SCIENCE AND ASSIST IN DEVELOPMENT OF IMPROVED MANAGEMENT PRACTICES. PROPOSED RESEARCH WILL FILL A CRITICAL KNOWLEDGE GAP IN BEEF CATTLE AND IMPROVE PRODUCTION EFFICIENCY, INCREASING AGRICULTURAL PRODUCTION TO MEET THE NEED FOR AN INCREASED GLOBAL FOOD SUPPLY.