CONCERNS REGARDING THE HEALTH AND WELFARE OF FARM ANIMALS HAVE GROWN SIGNIFICANTLY OVER THE LAST FEW DECADES. ANIMAL HEALTH AND WELFARE ARE TYPICALLY EVALUATED THROUGH VARIOUS INDICATORS SUCH AS PHYSICAL HEALTH, IMMUNE RESPONSE, BEHAVIOR, AND OTHER PHYSIOLOGICAL MARKERS, INCLUDING THOSE RELATED TO STRESS. THE STRESS EXPERIENCED BY SOWS DURING PREGNANCY CAN HAVE A LASTING IMPACT ON THE PHYSIOLOGY AND BEHAVIOR OF THEIR OFFSPRING, BOTH BEFORE AND AFTER BIRTH, POTENTIALLY LEADING TO LONG-TERM HEALTH AND WELFARE ISSUES LATER IN LIFE. THE GUTMICROBIAL ENVIRONMENT, OR MICROBIOTA, HAS BEEN SHOWN TO HAVE A SIGNIFICANT IMPACT ON HOST PHENOTYPES. NEVERTHELESS, THE GUT MICROBIOTA, WHICH PLAYS A CRUCIAL ROLE IN INFLUENCING THE BRAIN AND IMMUNE SYSTEM AND ULTIMATELY AFFECTS BEHAVIOR AND OVERALL WELL-BEING, IS FREQUENTLY OVERLOOKED IN WELFARE EVALUATIONS. IT HAS BEEN PROPOSED THAT THE MATERNAL MICROBIOME AND THE METABOLITES IT TRANSFERS ARE ESSENTIAL IN PREPARING THE NEONATE FOR OPTIMAL INTERACTIONS BETWEEN HOST AND MICROBES, WHICH IN TURN INFLUENCE IMMUNE FUNCTION AND BEHAVIOR LATER IN LIFE. HOWEVER, DATA ARE SCARCE REGARDING THE IMPACT OF PRENATAL STRESS ON THE MATERNAL MICROBIOME-IMMUNE AXIS, WHICH IS CRITICAL FOR DETERMINING THE HEALTH AND WELFARE OUTCOMES OF THE OFFSPRING. EXPLORING THE EFFECTS OF MATERNAL STRESS ON THE GUT-BRAIN-IMMUNE AXIS PRESENTS A NOVEL METHOD FOR ASSESSING ANIMAL WELFARE; THEREFORE, THE DATA GATHERED FROM THESE PROPOSED STUDIES CAN BE UTILIZED TO EVALUATE AND IMPROVE POOR WELFARE CONDITIONS SYSTEMATICALLY. WE WILL FOCUS ON THE FOLLOWING SPECIFIC OBJECTIVES: (A) TO IDENTIFY THE ROLE OF THE GUT MICROBES-IMMUNE AXIS IN STRESSED SOWS ON THE COLONIZATION OF THEIR PROGENY, (B) TO CHARACTERIZE THE EFFECTS OF VARIOUS STRESSORS ON THE MICROBIOTA-BRAIN-IMMUNE AXIS IN OFFSPRING BORN TO STRESSED SOWS, AND (C) TO DECIPHER THE MOLECULAR MICROBIOTA SIGNATURES ALONG WITH GUT-IMMUNE AND BEHAVIORAL PHENOTYPES THAT ARE IMPRINTED ON THE PROGENY IN SUBSEQUENT GENERATIONS. THIS DATA WILL CONTRIBUTE TO ENHANCING OUR UNDERSTANDING OF THE MATERNAL MICROBIOME AND THE EFFECTS OF STRESS RESPONSIVENESS ON MICROBIAL-BRAIN-IMMUNE SIGNATURES IN THE OFFSPRING, WHICH MAY INDICATE IMPROVED HEALTH AND WELL-BEING.