Wildfire smoke has an impact on milk production in cows, researchers find

Not only is the milk production impacted, but the cattle's health is deteriorating when exposed to wildfire smoke too.

Researchers at the University of Idaho found that dairy cows produce less milk after exposure to wildfire smoke. Not only is the milk production impacted, but the cattle's health is deteriorating when exposed to wildfire smoke too. 

Graduate student Ashly Anderson, Assistant Professor Amy Skibiel and Assistant Professor Pedram Rezamand are leading the effort to see how poor air quality due to wildfires impacts the health and production of dairy cattle. 

"In the Pacific Northwest, it’s particularly important because we have seasonal wildfires, so this is an annual exposure for both people and animals," Anderson said. Anderson is an animal science graduate student at the University of Idaho College of Agricultural and Life Sciences. 

From July to September of 2020, the team monitored 28 Holstein cows and their calves during smoke exposure. Holstein cows are known as the most common dairy breed in the U.S. 

Skibiel said that blood samples were taken before, during and after the smoke exposure. Doing so, they were able to track immunological markers and other blood metabolites to determine changes in response to particulate matter from wildfire smoke. 

They also monitored gestational effects on the calves in utero and from birth to weaning.

What they found was alarming.

"Changes were found in the cattle when the particulate matter was high due to wildfire smoke. Cows were producing three pounds less milk than previous weeks," Skibiel says. Skibiel specializes in research of lactation biology, maternal effects and performance.

There were also changes to the cattle's immune system and their blood, along with an indication of inflammatory response after the exposure. 

Skibiel says that they continue to monitor the cattle during smoky conditions to see if any trends persist. 

"It's hard to predict what the next several years are going to look like," Skiebel said. "If wildfires continue to increase, which they will, then I think we can safely assume that this is going to continue to be a problem in the future."

The team is expanding their research to farms in Washington, Oregon, northern California, Wyoming, Montana and southern Idaho. They hope to continue to increase the sample size to see if the trend persists. 

"We hope to eventually be contributing to a larger body of work that helps to improve cow comfort and cow health while also maintaining production for producers," Anderson says. "Due to climate change and global conditions, we’re going to be seeing a lot more wildfires and because of that, there are going to be a lot more people and animals exposed to wildfires. Being able to tell what kind of effects there are and how we might be affected in the future is very important."

Their research hopes to provide livestock producers with recommendations and advice to keep their cattle healthy during wildfire season.