A urease inhibitor reduces ammonia emission in fattening pigs reared on slatted floor in summer conditions

Abstract

Intensive pig farming is a main contributor to ammonia (NH 3 ) emissions. Urease inhibitors block the conversion of the excreted urea into ammonium and may reduce effectively these emissions at the housing level. This study evaluated the effect of applying a urease inhibitor in a naturally ventilated and fully slatted pig house. Emissions were compared using two approaches: in-time evaluation and case-control approach. Two identical rooms in size and management were used in this experiment. Seventy growing pigs of 70 kg weight were placed in each room. One room was treated with the urease inhibitor EBN (based on phosphorodiamidate) during 12 days (treatment phase) at a rate of 0.17 mL m −2 day −1 . The study also included a pre-treatment phase of 2 days and a post-treatment phase of 15 days. Temperature and concentrations of NH 3 and carbon dioxide (CO 2 ) were recorded every 2 min, and then aggregated on an hourly basis. Natural ventilation rate was calculated using the CO 2 balance method. The case-control approach showed more reliable results since only two days were available for the in-time approach. On average, emissions were reduced by 29% over the treatment phase. After each application, the maximum abatement potential was found between 4 and 14 h after application of the inhibitor. This study was conducted under specific farm and climate conditions. More studies are needed to confirm the abatement potential in a wider range of situations. • A urease inhibitor was tested in a naturally ventilated pig farm in summer conditions. • In-time evaluation and case-control approach were used to assess the mitigation potential. • Urease inhibitor reduced ammonia emission by 29%. • Response time of ammonia abatement after application was quantified.