| Summary: | Dairy cattle are usually housed in naturally ventilated houses where removal of excreta is periodically performed. The aim of this controlled study was to compare the effect of two floor designs and three air temperatures (5, 15 and 25 C) on NH3, N2O, CH4 and CO2 emissions arising from cattle excreta deposition to the floor. Two scale models were built to simulate a level solid floor without urine drainage, and a slatted concrete floor. Following application of a mixture of urine and faeces, these two floor type models were subjected to a constant airflow rate (12.5 exchanges h 1 ) and gaseous emissions were measured over a 72-h period. Emissions of NH3, N2O, CO2 and CH4 increased significantly with air temperature with both floor type models and emissions of NH3, N2O and CO2 were significantly greater from the solid floor relative to the slatted floor at all temperatures considered. The cumulative NH3 (27e66% of total N applied) and CO2 (<19% of total C applied) emissions were greater from the solid floor than from the slatted floor (by 36% and 44%, respectively). The cumulative N2O (<0.1% of total N applied) and CH4 (<0.4% of total C applied) emissions were relatively low and CH4 values did not differ significantly between treatments. Cumulative greenhouse gas emissions (as CO2-equivalents) increased significantly with temperature but did not differ between the floor types.
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