Estimation of ammonia and methane concentrations in pig barns based on daily activities, physiological parameters and various growth phases of pigs

Abstract

The continuous increase in ammonia (NH3) and methane (CH4) concentrations in pig barns is primarily driven by the expansion of pig farming, which significantly contributes to the increase in greenhouse gases (GHG) in the atmosphere. Therefore, this experiment aimed to investigate the NH3 and CH4 concentrations based on daily activities, pig physiological parameters such as body mass (BM) and feed intake (FI), and various growing phases of pigs. Two independent experiments were carried out in two pig barns across 2022 and 2023. Both barns were equipped with biological and environmental management sensors (BEMS) and livestock environment management sensors (LEMS) to monitor the pigs' daily activities, indoor air temperature (IT), relative humidity (IRH), and NH3 and CH4 concentrations. The results of the study revealed that BM and FI had a strong positive correlation with NH3 (r > 0.84 with BM and r >= 0.85 with FI) and CH4 (r > 0.83 with BM and r >= 0.81 with FI) concentrations during both study periods. Moreover, it was observed that NH3 and CH4 concentrations were lowest in growing phase 1 (G1) and highest in growing phase 4 (G4). Additionally, it was found that the NH3 and CH4 concentrations were highest during the morning defecation (7 AM - 8 AM) and lowest during sleeping at night (9 PM- 7 AM) activity time. In conclusion, these findings provide crucial insights into the patterns of NH3 and CH4 concentrations in pig barns, which are valuable for improving pig production practices and environmental management strategies.