Gaseous emission during broilers raising according to floor material and litter budget

In order to determine gaseous emissions during broilers production, an experimental growing room was equipped to continuously monitor air extraction through fans installed on roof of the building. A group of 5000 broilers was disposed on concrete floor with a woodchips litter (240 m2). Fluxes of gases were continuously analysed using Non Dispersive Infra Red spectrometer for CH4, CO2 and N2O, and using acid trapping for NH3. All fan's flow were quantified with several methods according to the different depression's configurationsFan's working periods were detected by amperometric sensors and recorded with a datalogger which allowed the management of the solenoid valves and the data from NDIR spectrometer. Instantaneous sampling of inlet and outlet air were realised at least 3 times a week to be analysed at laboratory by using gas chromatography. The monitoring was carried out for the growing period (i.e. 35 days). Manure stayed on floors during 3 days after harvesting broilers. Additional investigations on litter's emissions were developed during the 1st and the 3rd day with accumulation chambers and chromatographic analyses. These investigations were made in the same time, both on the concrete floor room and on a beaten earth floor room, distinguishing sleeping, eating, and drinking areas. Carbon dioxide contents were varying from 0,7/0,8 % at the start of growing, to 0,2/0,3 % after 3 weeks growing (stop of air heating machines). Ammonia emissions over the growing period reached to 4,8.10-3 kg N-NH3 per animal, and showed different steps, which can be related to modifications in litter behaviour. Results of accumulation's method after harvesting animals showed only a decrease of N2O content from 1st to 3rd day, from 9.10-3 mg N-N2O.m-3 to 5.10-3 mg N-N2O.m-3, with first day higher concentration probably du to handling engine combustion. A mass balance including started litter, feeding, chicks, broilers, exhaust gas and manure was established to analyse influence of floor construction (+26 kg total Nitrogen in litter on beaten earth floor).