DETERMINATION OF FUNGAL SPORES AND DUST M ITES IN HAY AND STRAW USED IN CHILEAN HORSE FARMS

This paper describes the categorization of hay and straw used in 17 Ch ilean horse farms in the provinces of Valdivia and Osorno, Chile, acco rding to the presence of fungal spores and dust mites. Samples of mixe d grass hay, lucerne hay and straw were collected from each farm in Ma y, July, September, October and December, 1993. A total of 165 samples of mixed grass hay, 159 of lucerne hay and 87 of straw were studied. A hand held Burkard slit sampler was used to categorize samples as fol lows; I: negligible quantities of mould spores presents; II: small num bers of mould spores, mainly large-spored; III: large numbers of small size spores (respirable spores).The highest number of type III sample s as well as dust mites was observed in October. The high number of he avily contamined samples (type III) in Spring, represents a high risk potential for respiratory diseases in horses.