THE SWINE INDUSTRY IS FACING DECREASING SOW INVENTORY CONCURRENTLY WITH INCREASING SOW MORTALITY AND CULLING RATES. THIS POSES A THREAT TO SUSTAINABILITY AND SOCIAL LICENSE OF PORK PRODUCTION AS WELL AS TO ANIMAL HEALTH AND WELFARE. TO ADVANCE THE SWINE INDUSTRY WE MUST BEGIN SELECTING REPLACEMENT GILTS THAT ARE ROBUST--RESILIENT TO THE MANY STRESSORS OF PORK PRODUCTION LEADING TO INCREASED SOW LONGEVITY AND ABILITY TO REACH THEIR MAXIMUM PRODUCTION POTENTIAL. WITH THE CRITICAL ROLE THAT THE PRENATAL ENVIRONMENT PLAYS IN SHAPING A RESILIENT ANIMAL AND THE SOCIAL STRESS FACED BY GROUP-HOUSING GESTATING SOWS, WE MUST BETTER UNDERSTAND THE ROLE A GESTATING SOWS' NATURAL ABILITY TO REGULATE STRESS PLAYS IN PROGRAMMING DAUGHTER PERFORMANCE.TO DETERMINE THE IMPACT OF SOW STRESS RESPONSE DURING GESTATION ON HER DAUGHTERS, THIS STUDY WILL FOLLOW DAUGHTERS OF STRESS RESILIENT AND STRESS VULNERABLE SOWS FOR UP TO FOUR PARITIES. STRESS HORMONES, REPRODUCTIVE HORMONES, DIRECT BEHAVIORAL OBSERVATIONS (INCLUDING POSTURE, STEREOTYPIES, AGGRESSION, AND SOCIAL INTERACTIONS), PROXIES FOR STRESS AND AGGRESSION, AND PRODUCTION OUTCOMES FROM FARM RECORDS WILL BE COLLECTED FOR EACH PARITY. DIFFERENCES BETWEEN RESILIENT AND VULNERABLE DAUGHTERS WILL BE USED TO ESTIMATE THE IMPACT OF MATERNAL RESILIENCE TO GESTATIONAL GROUP-HOUSING ON DAUGHTER LONGEVITY. ADDITIONALLY, ASSOCIATIONS BETWEEN THE VARIABLES MEASURED WILL BE ANALYZED TO IDENTIFY ANY MEASURES THAT ARE PREDICTIVE OF IMPROVED LONGEVITY.RESULTS OF THIS STUDY WILL FUEL THE DEVELOPMENT OF SELECTION STRATEGIES TO BREED MORE RESILIENT SOWS RESULTING IN A MORE ROBUST AND SUSTAINABLE SWINE INDUSTRY. KNOWLEDGE OF HOW BEHAVIOR IS ASSOCIATED WITH PHYSIOLOGY AND PRODUCTION OUTCOME GAINED FROM THIS STUDY WILL AID IN REFINEMENT OF PRECISION LIVESTOCK TECHNOLOGIES. IDENTIFICATION OF ANIMALS WITH INCREASED LIKELIHOOD OF POOR WELFARE OR POOR PERFORMANCE THROUGH AUTOMATED BEHAVIOR DETECTION WILL ALLOW EARLIER MANAGEMENT INTERVENTIONS--REDUCING COSTS TO THE PRODUCER. ONCE APPLIED, RESULTS OF THIS STUDY WILL GREATLY IMPROVE WELFARE OF FEMALES IN THE BREEDING HERD WHICH BENEFITS THE ANIMAL BUT ALSO SOCIETY. IN RECENT YEARS, CONSUMER ACCEPTANCE OF ANIMAL PRODUCTION AND THEREFORE SOCIAL LICENSE TO OPERATE RELIES HEAVILY ON MEASURABLE IMPROVEMENT OF WELFARE. OVERALL, THIS PROJECT WILL PROVIDE GUIDANCE IN HOW TO ENACT INDUSTRY-WIDE CHANGE TO IMPROVE BREEDING HERD WELFARE AND LONGEVITY THROUGH IDENTIFICATION OF RESILIENT DAMS, MANAGEMENT OF REPLACEMENT GILTS AND GESTATING SOWS, AND REVEALING TRAITS TO TARGET IN GENOMIC SELECTION.