engleski

Airborne dust and endotoxin in dairy cows stable

Airborne dust and endotoxins in animal houses are significant pollutants with a potential health risk for animals and humans working in these facilities. Study assessing the level of airborne contamination in dairy cows stable. The content of airborne dust and endotoxin was determined. The study was conducted in a dairy stable, dimensions 17.00x14.00x2.5 m. During the study, there were 25 Simmental lactating cows and 5 calves in the stable. Measurements were done in the morning (before feeding and milking) and in the evening, once a week, during two winter months. Measurements were performed in the stable, in the area of animal stay along the feedlot. Air temperature (°C), relative humidity (%) and airflow rate (m/s) were determined by use of a TESTO device (Testo Inc., Germany). Dust was sampled onto filters (Whatman International Ltd., Maidstone, UK) by use of an SKC pump (SKC Ltd., Blandford Forum, UK). The airflow rate was 4.0 L/min. Filters were weighed before and after sampling in a controlled laboratory at air temperature of 22 °C and relative humidity of 45% (± ; ; ; 5%). Air samples were stored at -20 °C for 2-3 months until endotoxin analysis. Endotoxin was analyzed using the end-point Limulus amebocyte lysate method (LAL).The measured parameter values were processed by use of Microsoft Excel and Statistica 6 software. The analysis included descriptive statistics and statistical significance set at 1% (p<0.01 by use of Student's t-test). The highest airborne dust concentration in the dairy cows stable was recorded in the evening (3.7 mg/m3), with statistically significant differences between morning terms of measurement (p<0.01) when were noticed 1.0 mg/m3 of dust. The measured levels of airborne endotoxins vary from 49 EU/m3 in the morning to highest values in the evening (550 EU/m3). The concentrations of airborne dust and endotoxin were higher in the evening measurement terms which can be related with activities in the stable (feeding, milking, manure removing). The level of airborne dust and endotoxin in dairy cows stable is significantly influenced by the cows number and activity, ventilation, air temperature and air humidity. Throughout the study period, the concentration of airborne endotoxins was below the levels reported in the literature.

dust; endotoxin; dairy cows; air quality

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