Clearing the Air

In recent years, wildfires have become an increasingly visible part of life across many regions of the United States. From the devastating Los Angeles fires in January 2025 to the major fires near the Grand Canyon during the 2025 wildfire season, millions of people have witnessed how wildfires burn vast landscapes and destroy infrastructure. Smoke from these fires can travel long distances, affecting air quality far beyond the areas where the fires occur. While wildfire smoke often receives attention for its impacts on human communities, its consequences for agricultural systems, particularly livestock, are only beginning to receive attention. This is especially concerning for major dairy-producing states such as California, Wisconsin, Idaho and New York, which together house nearly 2.9 million milking cows. Increasingly, dairy producers in these regions must manage the challenges of poor air quality caused by wildfire smoke.

My research as a PhD candidate and FFAR Fellow at the University of Idaho focuses on understanding how wildfire smoke affects respiratory health, immune responses, and metabolic function in dairy cattle.

Wildfire smoke contains a complex mixture of pollutants, including fine particulate matter known as PM_2.5 and various toxic gases. These tiny particles are small enough to penetrate deep into the lungs and are well known to cause respiratory disease and increased mortality in humans. Interestingly, studies suggest that PM_2.5 originating from wildfire smoke may be even more toxic than particulate matter from many other environmental sources. Wildfire smoke also carries a unique microbial profile, meaning that animals exposed to smoke may inhale not only chemical pollutants but also unfamiliar microorganisms. Despite these risks, research on the effects of wildfire smoke in livestock remains limited. Some studies suggest that wildfire smoke exposure can negatively affect animal health, increasing respiratory disease and mortality. In dairy cattle, evidence indicates that wildfire-PM_2.5 exposure reduces milk production, alters milk composition and impairs growth in young animals. However, the underlying biological mechanisms behind these effects remain largely unknown.

Understanding these mechanisms is increasingly important as wildfires become more common in regions that are critical to U.S. milk production. Beyond animal health concerns, wildfire smoke may also create significant economic challenges for dairy producers.

In a recent study conducted by our research group, we examined the relationship between wildfire-related air pollution and milk production in lactating Holstein cows. Our results showed that for every 100 μg/m³ increase in wildfire-PM_2.5, milk yield decreased by 1.20 ± 0.41 kilograms per cow per day immediately following exposure, with effects lasting for at least two weeks.

At a milk price of $0.44 per kg, this corresponds to an average estimated revenue loss of ~ $0.71 per cow per day. For a 1,000-cow herd, this translates to approximately $10,000 in total milk revenue losses over two weeks.

My research focuses on understanding the physiological mechanisms behind these production losses. Using tools to measure respiratory functional values such as spirometry, we have evaluated lung function in lactating dairy cows during periods of wildfire smoke exposure. Our findings suggest that when air quality deteriorates, cows begin breathing more rapidly but with shallower breaths, likely attempting to maintain adequate oxygen exchange while minimizing inhalation of harmful particles. At the same time, we observe signs of immune system activation, suggesting that exposure to polluted air may trigger inflammatory responses within the body. These findings highlight an important and often overlooked aspect of wildfire smoke: its potential to disrupt animal health and productivity in agricultural systems. As wildfires become more frequent and severe, understanding how air quality affects livestock will be essential for developing strategies that help producers protect their animals and maintain sustainable food production.

Through my research as a FFAR Fellow, I have been able to communicate the scientific outcomes of this work on an emerging environmental threat to U.S. dairy producers and the broader industry. This experience has allowed me to leverage effective science communication to translate research findings into informative, industry-relevant outputs that can support actionable mitigation strategies and strengthen producers’ resilience to environmental challenges.