Effect of ventilation settings on ammonia emission in an experimental pig house equipped with artificial pigs

The aim of this study was to compare the impact of 3 ventilation set-point temperatures (T set  = 21, 23 & 25 °C) on indoor climate and NH 3 emission, using 2 pig compartments with underfloor air distribution (UFAD) and equipped with artificial pigs. The artificial pigs consisted of mock-up pigs to simulate heat production and a spraying installation to mimic pig urination by applying urea solution onto the fully slatted pen floors in the test compartments. The study identified ground channel temperature (T GC ) as a key factor affecting NH 3 emission (P  GC also interacted with T set (P  3 emission. When the reference T set increased from 23 °C to 25 °C, NH 3 emission decreased by 43% at T GC 15 °C and 29% at T GC 18 °C, due to the relative reduction in ventilation rate (VR). At T GC of 22 °C, NH 3 emission did not differ between T set (23 °C) and T set (25 °C). However, when the reference T set decreased from 23 °C to 21 °C, NH 3 emission did not differ between the 2 set-point temperatures at T GC of 15, 18 and 22 °C. Further tests under practical conditions are needed to confirm these findings and to check for the impact of T set on pig performance and carcass quality.