Effect of urease inhibitor application on urease activity in three different cubicle housing systems under practical conditions

• The quantification of urease activity was suitable for practical use.
• Inhibitor application with a concentration of 2.5 mg m−2 proved to be sufficient.
• Temperature dependence of the urease activity has been demonstrated.
• The relative reduction of urease activity was 80% among different seasons.
• Use of urease inhibitor reduced the urease activity and with it the NH3 emissions.

The reduction of ammonia emission from animal husbandry is required due to detrimental and harmful effects on environment, health and fertilizer value. Nevertheless, practicable measures with a high ammonia mitigation potential, which can be implemented in existing dairy housing systems without significant constructional changes, are still rare. A possible reduction option, not previously used in practice, is the application of urease inhibitors on floor surfaces in dairy houses. Urease inhibitors inhibit the enzyme urease, which is responsible for the release of ammonia. It can, therefore, be assumed that a reduction of the urease activity always results in ammonia mitigation. Cubicle housing systems for dairy cattle differ in technical, climatic and organizational conditions. Consequently, tests on three different housings in three seasons have been carried out in the current study to evaluate the use of urease inhibitor in practice. The effect of the urease inhibitor was investigated based on detection of urease activity. A significant correlation of floor surface temperature and level of urease activity was observed. The current study shows that the application of a novel urease inhibitor resulted in overall average reduction of urease activity of 80% at dairy housing systems and at different seasons.