Odor Emissions from Cattle and Swine Slurry

In a systematically designed experiment, slurry from swine and cattle stalls was collected and frozen. After thawing, samples of both slurry types were temperated exactly at 10°C, 20°C and 30°C in a water bath and stored there for 24 hours. Odor samples were taken from the airspace above the slurry samples and analyzed with the olfactometer MANNEBECK TO 7, with reference to odor concentration, odor intensity and hedonic odor tone. It turned out that cold slurry emits less odorants, but these substances cause already at minor concentrations intensive and unpleasant smells. Warming up of slurry leads to a significant rise in odor concentration. The measured odor concentration of swine slurry at the defined conditions was always higher than that of cattle slurry. Both slurry types were perceived at equal concentrations with similar intensity, but compared to cattle slurry, the hedonic odor tone of swine slurry became more unpleasant with increasing odor concentration.