Microbiological Assessment of Air Quality in Barns with Different Dairy Cattle Housing Systems in the Context of Sustainable Safe Food Production

The study aimed to assess the microbiological quality of the air in three barns that differed in size, housing system, and number of animals in the context of sustainable and safe food production. Air samples were collected four times a year (spring, summer, autumn, and winter) to account for seasonal variations. The abundance of selected microorganisms (mesophilic aerobic bacteria, mold fungi, actinomycetes, Staphylococcus spp. and E. coli ) was determined using the impact method and appropriate microbiological media. Simultaneously, the air temperature, relative humidity, and real-time resistive sensor readings for current bioaerosols were measured in the tested rooms. Byre (III) had the lowest mean resistive sensor reading for bioaerosols, while barn (II) had the highest. The mean temperature was lowest in barn (I) and highest in barn (II). The mean relative air humidity was lowest in barn (III) and highest in barn (I). The 60 m 2 barn had the highest number of microorganisms. Factors conducive to the proliferation of microorganisms in the barn included the use of deep litter, which was removed once a quarter. Additionally, storing manure in close proximity to the barn contributed to an increase in the number of microorganisms in the livestock facility. No excessive air pollution with bacteria or mold fungi was found in any of the studied barns. Overall, the study demonstrates that barn management practices, litter type, microclimatic conditions, and ventilation significantly influence airborne microbial concentrations. These findings provide practical insights for improving environmental hygiene and animal welfare in barns and promoting sustainable development in dairy cattle farming.