Abstract

The aim of this study was to assess the microbiological quality of the air in tie-stall dairy cattle barns and to investigate some factors that influence it. We evaluated 52 dairy cattle barns with tie-stalls, during two years, in the winter period. The number of bacteria and fungi was slightly higher in the evening in comparison to the one in the morning and significantly higher in large barns (P<0.01), with bedding (P<0.01) and dirty (P<0.05). Both in the morning and in the evening positive correlations were observed between temperature and airborne bacteria, relative humidity and fungi. The prevalent species of bacteria were Staphylococcus epidermidis, Staphylococcus xilosus, Aerococcus viridans, Enterococcus faecalis, Enterobacter agglomerans andEscherichia coli. Among fungi, Aspergillus, Penicillium and yeasts predominated. This study’s results showed that the number of bacteria and fungi is variable and high in many cases in the indoors air of dairy cattle tie-stall barns, with the predominance of gram positive bacteria. Many of the identified bacterial and fungal species have pathogenic potential, posing risks for the health of animals and humans. Based on the obtained results, we consider the improvement of barn hygiene to be the most practical recommendation for decreasing concentrations of bacteria.

Key words: Airborne bacteria, airborne fungi, indoor air quality, barn hygiene.