The influence of hay-packing techniques on the presence of Saccharopolyspora rectivirgula

Environmental factors influencing the growth, distribution and viability of thermophilic actinomycetes, especially Saccharopolyspora rectivirgula as a n agent of extrinsic allergic alveolitis in farms workers, were studied. To tal microbial count, eumycetes and thermophilic actinomycetes were determin ed on 96 hay samples, randomly collected, from small prismatic and large cy lindrical bales, 30 air samples before and after animal feeding, and variou s surfaces in two farms located in the province of Reggio Emilia, Italy. Th e number of thermophilic actinomycetes (potentially responsible for hyperse nsitivity pneumonitis) was higher in hay samples from large cylindrical bal es than in those from small prismatic bales. The structural characteristics of the buildings (barns with stalls, poor ventilation) and the feeding pra ctices (manual handling of hay, constant presence of hay in feedings corrid ors) contributed to the dispersion of high levels of thermophilic actinomyc etes spores (potentially responsible for extrinsic allergic alveolitis). Th e ventilation system proved to be inadequate in reducing the number of micr oorganisms present.