The University of Idaho is researching the affects of smoke on cattle, some preliminary results showing decreased milk production.
Stephani Gordon / OPB
We know smoke can have detrimental effects to our body’s physical and mental health, but how is it affecting Oregon cows? Researchers in Idaho are now looking into some of the effects of wildfire smoke on cattle with some preliminary findings on milk production and health. We’ll speak with Amy Skibiel, a professor at University of Idaho, and Zach Rose, a dairy farmer at Rogue Creamery.
This transcript was created by a computer and edited by a volunteer.
Dave Miller: Over the last few weeks, we’ve talked about the effects of wildfire smoke on people’s physical and mental health. We also heard from a researcher who’s looking into its effects on grapes and winemaking. Today, we’re going to turn to another agricultural impact. That’s the subject of concern and study in the Northwest right now, dairy cows. Amy Skibiel is studying this at the University of Idaho, where she is an Assistant Professor of Lactation Physiology. Zach Rose is dealing with this professionally. He is the dairy farm Manager at Rogue Creamy. It’s good to have both of you on the show.
Amy Skibiel: Thanks for having me.
Zach Rose: Thanks for having us.
Miller: So Zack Rose first, how smoky has it been at your dairy on the worst days over the last few years?
Rose: To the point of zero visibility really. Not quite as bad as we had in Salem I would say last year, but pretty, pretty darn black and it changes the weather dramatically to where it’s cold.
Miller: Do you see behavioral changes in your cows on those worst days?
Rose: Yeah. We’re an organic dairy farm and we graze predominantly 66% of the year and during those times we can’t convince our cattle to go outside. They want nothing to do with that. They prefer to stay in the barn and stay out as much as they can of the weather.
Miller: But in the barn I imagine they still are exposed to smoky air or is it somehow filtered?
Rose: It’s not really filtered, it’s still the same year that they would breathe outside, but the conditions in the barn are that the food is there, the beds are nice and clean and there is dry fresh water. Accessibility to the milking robots is all within 100 steps of one another so they don’t have to work nearly as hard to take the feed they need on a day to day basis and to do their jobs.
Miller: So you saw certain behavioral changes, they didn’t want to go out in the past year. What about the physical effects from the smoke?
Rose: Two things that I’ve noticed specifically in the last four years of working at Rogue Creamery is we see an average of two to five pounds drop per day per cow during really, really smoky conditions. The other effect that we’ve seen specifically in ‘18 more so than ‘19, ‘20 and ‘21 was pneumonia. You notice when it’s really heavy that it’s hard for you to breathe, but you don’t really take that into consideration for pets or animals as well. That’s something that we’ve noticed was huge in ‘18 and what we’ve done to changes is that we’ve really pushed to make sure that we’re getting our vaccines in for the three or four different types of pneumonia that we can vaccinate for, but also just making sure constantly that they have a clean, dry place to sleep, fresh water with the water troughs cleaned twice a day, fresh food twice a day and that everything is just as clean and sterile as it can be to reduce the other effects that can contribute to pneumonia.
Miller: What does pneumonia mean for a cow?
Rose: It’s very similar in terms of what it does to a human. It takes a lot out of them, especially in their lungs. But for us, we’re organic, so treatment is the last course of opportunity to do anything for a cow. You know, it’s humane to treat the animal but then we’re forced to sell it to another dairy farm that’s conventional or to slaughter. And so for us it’s not an affordable method to let that go. So vaccinating and again, keeping everything clean and dry and keeping the cows as comfortable as possible is our ultimate goal at the end of it.
Miller: Amy Skibiel, my understanding is that you came to the University of Idaho from Florida where I imagine smoke wasn’t near the top of the list of concerns for dairy farmers.
Skibiel: That is correct. In fact, in Florida, I was studying heat stress, which is much more of a prevalent issue in Florida than smoke.
Miller: So what convinced you to start to look into the effects of smoke on dairy cattle?
Skibiel: Yeah, thanks for that question. So, this topic, this idea for this. These projects came out of a conversation that I had with a colleague of mine Dr. Pedram Rezamand, who had been noticing wildfire smoke in the area for the past 10, 15 years here consistently every summer and wondered what effect that was having on the cattle. With myself being a lactation and environmental physiologist, I of course was very interested in this potential issue. So we together started projects to investigate the effects, given that we know that there are health impacts in humans, we anticipated that that would be the case for dairy cows as well, who do not have the capacity most of the time to escape from areas of poor air quality. And so that’s what precipitated these studies.
Miller: My understanding is that you’re doing two similar overlapping but separate studies, one looking into the overall health of cows and one looking into their milk production. So let’s take those one by one. First of all, what have you been finding out about how smoke affects their overall health?
Skibiel: Sure. So we conducted just a preliminary study looking at the past five years of farm records from two farms in the Pacific Northwest, one in Washington and one in Idaho. And we just looked for associations between increases in particulate matter from wildfire smoke and various illnesses, diseases, general illness, pneumonia, mastitis and so on, in an association with those wildfire smoke events.
Miller: And did you find a connection?
Skibiel: We did. We found connections between high particulate matter from wildfires and general cattle illness. We also found associations between mastitis which is an utter infection and high particulate matter. We also found associations between calf mortality rates and high particulate matter. So when particulate matter from wildfires are high, we see higher incidences of general illness and cattle and higher mortality and calves.
Miller: Mortality is final obviously, obviously, but the others seem like they could be short term effects from high particulate days or weeks. Do you know much yet about long term effects on the effect of on cow health?
Skibiel: Somewhat. Right now we have been just focusing on two weeks post wildfire events, so we don’t really know much beyond that. However, there are some other studies in dairy cattle, just a couple, that have looked at just general ambient air pollution and associations with cattle illness and mortality. And they found that there were long term effects weeks if not months after high particulate matter. But again, that was particulate matter from ambient air pollution, not from wildfires. We know that there are obviously differences in the composition of air pollutants depending on the source. And so we really need to be studying the effects of wildfire smoke specifically. That’s going to have a different signature of air pollutants.
Miller: What did you find in terms of milk production?
Skibiel: What we found in terms of milk production actually corroborates what Zach just mentioned. We found that during a seven day wildfire event last summer that cows were producing on average about three pounds less milk per day per cow.
Miller: This is one of many things I learned for today’s show that dairy farmers measure volume of milk or measure the production of milk from their cows in pounds, not in gallons. Zach Rose, how big a drop? How significant is three pounds less per cow per day for a dairy operation?
Rose: For us it’s substantial. We only milk 120 head of cattle. You’re looking at 360 to 400 to 500 pounds of milk loss in a single day. That adds up very quickly to 600 to 1,000 pounds every other day, which is the way we ship our milk to our creamery. Those numbers are huge. That’s $54 of loss for me per 100 pounds of milk. That’s a huge loss in terms of my profitability, but also the grounds that I have to make up because what we see is the loss, what we find is another 7 to 14 days when the smoke events dissipate to rebound in terms of production in some cows that are further along the medication don’t rebound from that. So it’s huge, not only just during that window, but a recovery period thereafter.
Miller: Just briefly Zach Rose, when we talked last week about the effects of smoke on grapes and wine makers, we talked about the fact that sometimes grapes could be tainted with the smoke in a way that lasts into the wine. Does that happen with milk?
Rose: No, I wouldn’t say so, but what I find funny about that is that in one of our cheeses we use a Syrah grape leaf and we wrap the cheese in that. Those years that it’s super smoky, it’s hard to find the right leaves as we picked them. They just don’t have that flavor profile. That kind of contributes to our product.
Miller: After the fact, after the fact you get a smoky cheese just from smoke on the leaf. Zach Rose and Amy Skibiel, thanks very much for joining us today.
Skibiel: Thank you.
Rose: Thank you very much.
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