engleski

Bacteriological air quality in the pig fattening unit

Intensive pig rearing in confined spaces influences the composition of air that can serve as a potential carrier of respiratory infections. Therefore, investigations from this field are necessary to establish possible differences in microbiological air quality during the day and the effect of population density on these values. Investigation was conducted in the fattening unit of 450 m2 with negative pressure ventilation throughout two production cycles with small and large number of animals, during which the total number of mesophylic bacteria in the level of animal biozone and in a defined time period was established. Fattening unit was equipped with a total of 44 pens, measuring 2.85 m x 2.5 m (7 m2). In the first/second production cycle 460/505 animals were evenly distributed. The measurements in both stages were conducted during three time periods: morning (8 - 10 o'clock), afternoon (13 - 15 o'clock) and evening (19 - 21 o'clock) for every 10 days throughout the 110 days of fattening. The air was sampled onto growth medium for the isolation of total mesophylic bacteria with the SAS 100TM (PBI International, Italy) device, after which their numbers were established in the laboratory with standard analytical methods. Primary microclimatic parameters and animal health status were monitored through both production cycles in the investigation. According to the analysis of experimental data, elevated bacteria numbers were established in the production cycle with larger number of animals per unit of floor space, but not in a degree that would negatively affect their health. At the same time the bacteria levels were reaching peak values during the afternoon in both production cycles. It has been concluded that in identical housing conditions animal density influences airborne bacteria numbers, whereat their daily values increase alongside an increase in animal activity.

pigs; fattening unit; airborne microbes; health; animal activity

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