EFFECTS OF SOAKING HAY FODDER FOR HORSES ON DUST AND MINERAL-CONTENT

Four bales of hay were chosen from a stack of hay, barn-stored for 6 m onths. Each bale was subdivided into four 2.5 kg sections and one sect ion from each bale was subjected to one of four water soaking treatmen ts: 0, 0.5, 3 or 12 h. Post treatment, the samples were shaken for 9 m in under a Negretti LS45F personal dust sampler which sampled the surr ounding air. The samples were than analysed for levels of respirable p articules <5 mu m in size and for amounts of sodium (Na), potassium (K ), phosphorus (P), magnesium (Mg), calcium (Ca) and nitrogen (N). Soak ing for 30 min reduced the number of respirable particles by about 90% but also reduced the Na, K and P content of the hay. Soaking for a lo nger period, at least up to 12 h, did not give a significant further r eduction in number of respirable particles by about 90% but also reduc ed the Na, K and P content of the hay. Soaking for a longer period, at least up to 12 h, did not give a significant further reduction in num ber of respirable particles but there was loss of Mg and further losse s in Na, K, and P. These results clearly indicate that soaking for 30 min is sufficient to reduce the respirable challenge with minimum nutr ient loss.