** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** WILDFIRES ARE BECOMING AN INCREASING PROBLEM ACROSS THE GLOBE. LANDSCAPE CHANGES AND A DRIER, HOTTER CLIMATE ARE CONTRIBUTING TO AN INCREASE IN THE NUMBER AND SEVERITY OF WILDFIRES. OVER THE PAST DECADE IN THE U.S., THERE HAS BEEN AN AVERAGE OF 63,000 WILDFIRES PER YEAR THAT BURNED 7.5 MILLION ACRES ANNUALLY. EXPERTS ARE PREDICTING FURTHER INCREASES OVER THE NEXT CENTURY IN THE DURATION OF THE WILDFIRE SEASON AND IN THE NUMBER OF LARGE, CATASTROPHIC WILDFIRES IN THE U.S. WILDFIRES OCCUR FREQUENTLY IN THE WESTERN U.S., WHERE THERE ARE MORE THAN THREE MILLION DAIRY COWS THAT PRODUCE ALMOST 40% OF THE MILK IN THE U.S. THESE ANIMALS MAY BE LOCATED IN THE DIRECT BURN AREAS OR MAY BE EXPOSED TO THE SMOKE EMITTED FROM WILDFIRES, WHICH CONTAINS TOXIC GASES AND PARTICLES. INHALATION OF POLLUTANTS FROM WILDFIRE SMOKE CONTRIBUTES TO ILLNESS AND MORTALITY IN HUMANS AND RECENT RESEARCH INDICATES THAT WHEN DAIRY CATTLE ARE EXPOSED TO WILDFIRE SMOKE THEY HAVE ALTERED IMMUNE RESPONSES, LOWER MILK PRODUCTION, AND ADVERSE HEALTH OUTCOMES DURING AND IN THE WEEK FOLLOWING EXPOSURE. BEYOND THESE LIMITED STUDIES, THERE ARE CURRENTLY NO PUBLISHED DATA REGARDING IMPACTS OF WILDFIRE SMOKE INHALATION IN DAIRY CATTLE. GIVEN THAT WILDFIRES ARE EXPECTED TO CONTINUE TO WORSEN, IT IS IMPORTANT THAT WE UNDERSTAND HOW WILDFIRES IMPACT CATTLE AND CONSEQUENTLY HOW WE CAN MITIGATE OR PREVENT THOSE RISKS.OUR GOALS IN THE PROPOSED WORK ARE TO 1) DETERMINE HOW WILDFIRES CONTRIBUTE TO DISEASE AND IMPEDE OPTIMAL PERFORMANCE IN LACTATING DAIRY COWS IN THE SHORT AND LONG-TERM; 2) INVESTIGATE SHORT- AND LONG-TERM EFFECTS ON CALVES WHEN THEY ARE EXPOSED TO WILDFIRE SMOKE EARLY IN LIFE; AND 3) TEST THE EFFICACY OF A NOVEL DEVICE TO FILTER OUT AIR POLLUTANTS FROM WILDFIRE SMOKE. WE ANTICIPATE THAT WILDFIRE SMOKE WILL CONTRIBUTE TO INFLAMMATION IN COWS THAT CONTINUES AFTER WILDFIRE SMOKE EXPOSURE, CULMINATING IN DECREASED LUNG FUNCTION AND OVERALL ANIMAL HEALTH. THESE EFFECTS ARE EXPECTED TO BE DIMINISHED WHEN THE AIR COWS ARE BREATHING IS PURIFIED. FURTHER, WE EXPECT THAT CALVES EXPOSED TO WILDFIRE SMOKE EARLY IN LIFE WILL EXPERIENCE MORE SEVERE SYMPTOMS AND HEALTH EFFECTS THAN COWS SINCE THEIR IMMUNE AND ORGAN SYSTEMS ARE STILL DEVELOPING AND MATURING. WE ALSO ANTICIPATE THAT THESE EARLY LIFE EFFECTS WILL PERSIST INTO LATER LIFE STAGES. OUR RESEARCH WILL FILL A GAP IN KNOWLEDGE OF THE IMPACTS OF WILDFIRE SMOKE ON DAIRY CATTLE ACROSS MULTIPLE LIFE STAGES AND WILL PROVIDE NEEDED INFORMATION TO DEVELOP TOOLS AND STRATEGIES PRODUCERS CAN EMPLOY TO IMPROVE CATTLE HEALTH AND PERFORMANCE UNDER RAPIDLY CHANGING ENVIRONMENTAL CONDITIONS.