The Effect of Management Regime on Airborne Respirable Dust Concentrations in Two Different Types of Horse Stable Design

Abstract

a b s t r a c tAirborne respirable dust (ARD) (<5 mm) in the stable environment is strongly implicated in equine asthma. Bedding, forage, ventilation rate, and stable management activities all contribute to ARD. This study investigated the relationship between ARD in the breathing zone (BZ) and the stable zone (SZ) in eight American barns (ABs) and eight stable complexes with individual stables under four different management regimes. Airborne respirable dust was measured in eight replicate stables per regime in ABs (n ¼ 32) and eight per regime in single stables (n ¼ 32). Regimes were as follows: (1) steamed hay and shavings; (2) dry hay and shavings; (3) haylage and straw; and (4) dry hay and straw. Samples were taken in quite periods between 3 PM and 4 PM hours. Airborne respirable dust levels were analyzed using Split-Plot analysis of variance and Wilcoxon matched-pairs test (Genstat 15) with P < .05 as significant. The lowest ARD (<360 RP/L air) was found for shavings and steamed hay in AB and single stables in both BZ and SZ. Straw and dry hay in ABs produced ARD of 6,250 (SZ), 5,079 RP/L air (BZ) which was greater (P < .05) than the 2,901 (SZ) and 942 (BZ) RP/L air in single stables. Straw and haylage produced more ARD across both zones in single stables compared with ABs. Shavings and dry hay ¼ more dust in the BZ than in the SZ, whereas straw and haylage ¼ higher ARD in the SZ versus the BZ across both stable designs. Using dry hay and/or straw cannot be recommended as a suitable management regime for stabled horses.

Assessment of exposure to fungal aerosol in the lecture rooms of schools in the Lesser Poland region

“…Literature data show that an important parameter for assessing the effects of biological aerosols on the human body is the determination of the aerodynamic diameter of their particles. This feature determines their behavior and dynamics in the air, and thus determines their deposition in a specific space or on the surface (Auger andMoore-Colyer 2017, Górny et al 2020). The use of the 6-stage Andersen impactor in the bioaerosol research allowed us to obtain data on the size distribution of fungi in indoor and outdoor air in schools.…”

Environmental Management of Equine Asthma

“…One possible reason for this is the closer proximity of the nostrils to forage compared with bedding. However, another study [37] reports that using straw as bedding material further increases the ADC, compared to hay. Those discrepancies could be due to multiple factors, mainly to the different procedures used for measuring dust (RDC vs. ADC), but also to the quality of both straw and hay, the method of storage, or different barn architecture.…”

“…Changes in bedding (straw to wood shavings) but also in feed (hay to haylage, or soaking/steaming hay) have been evaluated altogether. These modifications cause a significant reduction in mean and maximum RDC and endotoxin levels [23,25,37,38,60], not only in the box of the changes, but also in the neighbouring stable [60]. Ionisation, a treatment that is believed to reduce dust and microbes by the agglomeration of smaller particles into larger ones, did not show an effect on dust quantity or air quality [23].…”

“…This is one of the problems of comparing studies that assess total and respirable dust because the results of measurements depend enormously on the zone from which they are taken. For instance, dust in the breathing zone of a horse is always higher than in samples obtained from a fixed point in the barn [37]. For that reason, a more standardised method of measurement should be employed to properly compare the results of different studies.…”

Bacterial aerosol, particulate matter, and microclimatic parameters in the horse stables in Poland

“…It is assumed that respirable fractions play a major role in the pathogenesis of asthma and RAO in horses (Fleming et al 2008;Ivester et al 2014;Pirie et al 2016). Additionally, it is believed that respirable fractions of both PM and bioaerosol, that is, with the aerodynamic diameter below 5 µm, reach the same locations in the airways of both horses and other animals (Clements and Pirie 2007;Hessel et al 2009;Auger and Moore-Colyer 2017).…”