Airborne Microorganisms in Tie-stall Dairy Barns from Brasov County

Abstract

The aim of this study was the assessment of the airborne microorganisms in tie-stall dairy cattle barns, through determination of the total number of bacteria (mesophilic bacteria, staphylococci, streptococci and gram-negative bacteria) and fungi. We investigated 8 dairy cattle barns with tie-stalls in Brasov County during the winter of 2009. The mean numbers of bacteria and fungi in the morning and in the evening were: 1.02 × 105 - 1.26 × 105 CFU/m3 for mesophilic bacteria, 5.34 × 104 - 5.91 × 104 CFU/m3 for staphylococci, 2.93 × 104 - 3.60 × 104 CFU/m3 for streptococci, 2.17 × 103 - 3.48 × 103 CFU/m3 for gram-negative bacteria and 1.54 × 104 - 2.75 × 104 CFU/m3 for fungi. In the investigated cattle houses staphylococci represented 52.35 – 46.90%, streptococci were 28.73 – 28.57%, and the gram-negative bacteria were 2.13 – 2.76% within the overall number of mesophilic bacteria. The numbers of bacteria and fungi were slightly elevated in the evening comparative to the morning, but the differences were statistically insignificant (p>0.05). The great numbers of bacteria and fungi in the air of dairy cattle tie-stall barns indicate an elevated risk of disease for animals and human workers.

Keywords

• airborne bacteria
• airborne fungi
• dairy cattle
• indoor air quality