Ammonia and Nitrous Oxide Emissions from Dairy Cows on Straw-Based Litter Systems

Increasing concerns regarding environmental impacts of animal production require a better understanding the factors that influence nitrogen (N) excretion by animals and processes N volatilization into ammonia (NH3) nitrous oxide (N2O) from manure. The objective this study was to evaluate diet characteristics climatic on manure composition, as well resulting NH3 N2O emissions in barn during storage straw-based litter system. Two groups three dairy cows were housed mechanically ventilated rooms fed with grass-based (GD) or total mixed (MD). solid manures stored tunnels. experiment conducted autumn (AUT) spring (SPR). recorded continuously (28 days barn, 85 for storage). NH3–N higher GD-AUT than MD-AUT, which consistent larger unbalanced amount crude degradable protein GD, corroborated milk urea contents. More 80% occurred first week storage, when temperature heap peaked. N2O–N negligible barn. During peaked immediately after week. Higher related rainfall, may have increased moisture content decreased heap, thus generating conditions necessary nitrification denitrification processes.