Techniques for reducing the respirable challenge in hay

Introduction: Reducing airborne respirable dust (ARD) from hay fodder is an important factor in the treatment of horses with equine asthma. Initiation of allergenic respiratory disorders in healthy horses could also be reduced by decreasing exposure to ARD in fodder by using suitable pre-feeding treatments. Objectives: To determine the effect of different wetting treatments on the ARD, microbial contamination, nutrient content and palatability of fodders for horses.

Methods: A variety of fodders, meadow and seed hays and haylage were subjected to the following treatments: dry, soaking in water, steaming in bags (kettle), steaming in bins and steaming in a proprietary hay steamer the Haygain in separate experiments. ARD was measured using a Munro personal sampler (AS 200, Woodford Green, Essex, UK),[1,2] microbial contamination (cfu/g) using culturing techniques with 3M petrifilms, (Carl-Schurz-StraBe 1, Germany), nutrient content [1,3] and palatability [4]. Additionally, different stable management regimes were tested for ARD [5] in American barns and single stables. Data was analysed using ANOVA and Wilcoxon matched-pairs t-test using Genstat, significance level were set at P<0.05.

Results [...]