**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** THIS PROJECT WORKS ON PREVENTION OR ALLEVIATION OF COLD STRESS IN LAYING HENS BY DEVELOPING AN ANIMAL-FRIENDLY METHOD. COLD STRESS IS A CRITICAL FACTOR AFFECTING LAYING HEN HEALTH AND PRODUCTIVITY. BASED ON THE CLIMATE CHANGE THEORY, COLD OUTBREAKS BECOME MORE FREQUENT DURING WINTER MONTHS. RESTRICTING OR REDUCING VENTILATION IN ENCLOSED BARNS, COMMONLY USED TO ALLEVIATE COLD STRESS IN HENS, INCREASES IN-HOUSE HUMIDITY, MANURE MOISTURE, AND AERIAL AMMONIA. THIS CHALLENGE COULD BE FURTHER EXACERBATED AS THE EGG INDUSTRY IS CONVERTING CONVENTIONAL CAGES TO CAGE-FREE SYSTEMS TO MEET HEN BEHAVIORAL NEEDS. PERCHES IN AVIARY SYSTEMS COULD BE MODIFIED TO IMPROVE HEN THERMAL COMFORT. CONDUCTIVE WARMING THROUGH ENCLOSED WARMED PERCHES COULD AVOID THE DISADVANTAGES OF RESTRICTING VENTILATION. IN THIS STUDY, HENS WILL BE ASSIGNED TO 1 OF 3 TREATMENTS: 1) CAGE WITH WARMED PERCHES, 2) CAGES WITH NON-WARMED PERCHES, AND 3) CAGES WITHOUT PERCHES. HENS WILL BE EVALUATED FOR SKELETAL AND FOOT HEALTH, FEATHER QUALITY, EGG PRODUCTION TRAITS, FEED EFFICIENCY, BODY TEMPERATURE, ENDOCRINE AND IMMUNE RESPONSES, CAUSES OF MORTALITIES, AND BEHAVIOR. ECONOMIC IMPACTS WILL BE ASSESSED. THE RESULTS FROM THIS STUDY WILL PROVIDE EVIDENCE THAT WARMED PERCHES REDUCE HEN MORTALITY AND IMPROVE EGG PRODUCTION AND EGGSHELL TRAITS SUING COLD WINTER MONTHS. OUR SUCCESS WILL PROVIDE CONSUMERS WITH ASSURANCE THAT HEN HEALTH AND WELFARE CAN BE IMPROVED UNDER THE MODERN POULTRY EGG PRODUCTION SYSTEMS; AND IT WILL PROVIDE EGG PRODUCERS WITH A NEW INSIGHT FOR DEVELOPING GUIDELINES AND PRACTICES.