Environmental and Animal-Related Parameters and the Emissions of Ammonia and Methane from an Open-Sided Free-Stall Barn in Hot Mediterranean Climate: A Preliminary Study

Abstract

Increased knowledge on the factors that affect emissions from open-sided dairy buildings may lead to an improvement of the mitigation strategies. In this study, ammonia (NH3) and methane (CH4) emissions were assessed in an open dairy barn in a hot Mediterranean climate at different managements of the cooling system, as well as the influence of environmental and animal-related parameters on daily emissions. Measurements of gas concentrations and micro-climatic parameters were carried out in a cubicle free-stall dairy barn located in the province of Ragusa (Italy) in two weeks of 2016 characterised by similar climatic conditions in the warm period. Emissions of NH3 and CH4 were estimated through the application of the carbon-dioxide (CO2) mass balance method. Data collected were organised in specific datasets to carry out different statistical analyses on gas emissions depending on selected parameters for the two weeks with a different management of the cooling system. The results showed higher NH3 emissions and lower CH4 emissions in W1 than those in W2. The variability in gas emissions was related to the effect of temperature humidity index (THI) (p < 0.001) and cow behaviour (p < 0.01). The highest emissions were recorded during the cleaning procedures for both NH3 (p < 0.001) and CH4 (p < 0.001), whereas the lowest emissions were recorded during the central hours of the day.