Juliana Ranches and Jenifer Cruickshank

This project seeks to investigate how exposure to wildfire smoke affects the productivity of dairy cows (milk) and beef cows (body weight and condition) and how it affects immune and stress markers in the blood. The study involves groups of 16 beef cows at the Eastern Oregon Agricultural Research Center at Burns and 16 dairy cows at the Oregon State University Dairy in Corvallis. The procedure includes:

• baseline phase (before smoke): every two-weeks, the cows are subjected to visual inspection (runny eyes? snotty nose?), blood draws, weighing (beef cows), and milk sampling (dairy cows)
• smoke phase (poor air quality): the above measurements and samples are taken every other day
• monitoring phase (after the smoke clears): the above measures and samples are taken once a week

Milk yield data are collected and the milk samples are analyzed for standard components plus a few extras. The blood samples are analyzed for various white blood cell concentrations, pro-inflammatory cytokines, acute phase proteins, immunoglobulins, and cortisol. (Are the cows experiencing stress that we can’t see just by looking at them?)

In the summer of 2021, baseline samples were taken from the dairy cows, but the air quality in Corvallis never got bad enough to enter the “smoke phase”. For the beef cow cohort, the air quality was never good enough for taking baseline samples, because the cows were “contaminated” by the smoke from the Bootleg fire, so we didn’t have any control samples. (Due to the timing of the funding, we couldn’t start until July.) So as not to waste resources, the collected blood samples remain, unanalyzed, in the freezer.

We will sample both the beef and dairy “smoke” groups through the fire season of 2022. While we don’t wish for wildfires, should they happen we will be collecting data.