WEST LAFAYETTE, Ind. – The 235 out-of-control Canadian wildfires, along with the stuck weather pattern of heat and humidity, created a meteorological mess of things for those in the Farm World readership area.

Meteorologists provide the public with an Air Quality Index, or AQI. The U.S. EPA calculates the AQI for five major air pollutants regulated by the Clean Air Act: ground-level ozone, particle pollution (also known as particulate matter), carbon monoxide, sulfur dioxide and nitrogen dioxide. Ground-level ozone and airborne particles are the two pollutants that pose the greatest threat to human health in this country.

An AQI between 0-50 is the good range, while an index of 51-100 is moderate. The “Unhealthy” range is between 101 and 200. Contaminates in this range plagued those living in Iowa, Illinois, Indiana Ohio and Kentucky the past two weeks. As of June 29, Canton, Ohio, had an index of 252. In Kokomo, Ind., it was 165. The reading in Louisville, Ky., was 157. Iowa City, Iowa posted a reading of 185.

Wildfires across the country have constantly made headlines over the past decade. 2020 had the most acreage burned in a single year, with 10.3 million acres burned by wildfires, according to the National Interagency Coordination Center. Cattle producers, especially in the western U.S., are acutely aware of the hazards of wildfire as the frequency and intensity of these events continues to increase. Changing grazing patterns, loss of feed supplies including pastures, and poor animal health are all major concerns when wildfires break out.

So, what about the effects on livestock in states like Iowa, Illinois, Indiana, Ohio, Michigan and Kentucky?

Jackie Boerman, associate professor of animal sciences at Purdue University, sat in on a presentation from University of Idaho professors Amy Skibiel and Pedram Rezamand, whose topic was “Responses to Health Parameters of Animals Exposed to Wildlife Particulate Matter.” Skibiel and Pedram reside in the heart of “wildfire country” and shared their findings with Boerman and others from the Midwest.

Particulate matter is found in wildfire smoke and is a known air toxin that can contribute to illness in humans, but dairy and beef cattle as well, said Skibiel, who specializes in lactation physiology and has seen immune cells responses to wildfire smoke in dairy cattle.

“Smoke inhalation has negative effect on circulating immune cells which can hinder the respiratory system, the first defense against smoke inhalation,” she said. “Temperature Humidity Index (THI) also compounds the effects of wildfire smoke. Our studies showed negative impacts on metabolism, milk production, and immune system function when cattle were exposed to either or both wildfire smoke and high THI.”

Skibiel added that milk yield was negatively affected, as were protein and butter fat. Blood components, including white blood cells and red blood cells, also changed when exposed to wildfire smoke and particulate matter.

Rezamand has performed extensive studies on the effects of particulate matter on dairy systems in the Pacific Northwest.

“Our research looks at the cellular physiological response and how wildfire smoke and particulate matter causes the reaction it does,” he said. “Pulmonary physiology is the same between dairy and beef cattle, even though the management systems are different.”

The two recently completed a similar study in dairy calves and found that wildfire smoke and high THI negatively impacted the immune system and increased the risk of respiratory symptoms such as cough and eye discharge just days after a wildfire event. The results were considered to be comparative since beef calves and dairy calves in the region are kept outside.

Rezamand’s experience in dairy nutrition also reveals how the immune system responds to stressors such as wildfire smoke. He said paying attention to vitamin and mineral status of feeds is essential to preparing the immune system before an environmental stressor occurs as antioxidant and anti-inflammatory properties will naturally occur with good nutrition.

Angela Green-Miller, animal welfare expert at the University of Illinois Urbana-Champaign, agrees that livestock may be at risk due to poor air quality from the Canadian wildfire smoke.

“In this region, we’re not used to dealing with polluted air,” she said. “We don’t typically have filtration in our houses or commercial indoor animal production facilities, although some poultry and pig facilities have implemented air filtration systems to control the spread of airborne diseases.

“Concerns for animals are similar to those for people. One of them being not overexerting yourself to avoid breathing deeper and pulling pollutants deeper into your lungs. So, don’t ride your horse because they’re going to breathe deeper and pull more particulates into their lungs. Most animals are not likely to suffer long-term consequences from the current situation, though those with pre-existing respiratory conditions are at a higher health risk.”