News Notes

Soaking Hay Helps Reduce Particular Matter Exposure in Stables

By Marie Rosenthal MS

Particulate matter (PM) is a leading cause of equine asthma, so being able to monitor the air quality in the barn could improve the management of equine asthma, according to researchers from Purdue University.

When confined to stalls, horses are typically fed hay, which is a source of PM sizes that are of concern: PM2.5 (particles with diameters less or equal to 2.5 μm), respirable dust (particles less or equal to 4 µm), and PM10 (PM with diameters of 10 μm), which have been implicated in respiratory issues among horses.

The researchers compared the custom-made PM monitor (Black Beauty [BB]), which measures the air quality around the horse’s head, with the tapered element oscillating microbalances (TEOMs), an instrument that measures the air quality of the barn and is considered the “gold standard,” to calibrate the effectiveness of the BB monitor, which is mounted on the horse’s halter.

The researchers compared the PM exposures of 10 horses fed dry or soaked alfalfa hay recorded for the first 20 minutes and 8 hours after offering feed. The horses were from the Purdue University teaching herd and reflected various breeds. They were between 6 and 23 years old and had a median weight of 542 kg. All were healthy and were acclimated to wearing the monitors.

The PM was higher during the first 20 minutes than 8 hours later, regardless of whether the hay was wet or dry. However, they found that feeding hay had been soaked, significantly reduced average exposures at both 20 minutes and 8 hours.

“The dust measurements with BB monitors were highly correlated to the ‘gold standard’ method and, therefore, is reliable and, more importantly, wearable, thereby, allowing monitoring of horses’ exposure to PM in their normal environment,” Laurent Couetil, DVM, PhD, DACVIM-LAIM, told the Modern Equine Vet in an email. Dr. Couetil is a professor of large animal medicine in the Department of Veterinary Clinical Sciences, Purdue University, College of Veterinary Medicine, in West Lafayette, Ind.

“With appropriate corrections, the BB monitor can be used to estimate horse PM exposure. While 20-minute measurements yielded higher estimates of exposure than 8-hour measurements, both intervals demonstrate that soaking hay reduces PM exposures by more than 50%,” the researchers wrote. MeV

For more information:
Ivester KM, Ni JQ, Couetil LL, et al. A wearable real-time particulate monitor demonstrates that soaking hay reduces dust exposure. Equine Vet J. 2024 October 27.
https://beva.onlinelibrary.wiley.com/doi/10.1111/evj.14425