Comparaison de l'utilisation de sciure ou d'un mélange paille-sciure comme substrat de litière accumulée pour porcs charcutiers

Two similar rooms were used to keep pigs on deep litter, one room with pigs on sawdust (litter S) and the other with pigs on a mixture of straw and sawdust with 50% dry matter (DM) of each material (litter PS). Three batches of 17 pigs were reared in each room over the 14-month period of experiment. The deep litters were started with a bedding of about 30 cm. Afterwards the amounts of litters used were adjusted to keep the pigs clean. Each week the litter S was manually aerated and manure incorporated in the litter. This work was not per formed with the litter PS. Both temperatures, relative humidities and ventilation rates were similar in the two rooms. The temperatures in the litters were continuously recorded. Ammonia concentrations were measured once a week using 8-h diffusion tubes. Electrochemical probes were occasionally used to measure the NH3 concentrations continuously, at l-h intervals, during 1-week periods. NO concentrations were measured dul-ing all the experimental period with electrochemical probes. At the end of the experiment the amounts of litter DM used per pig were of 32 kg with the litter S and 40 kg with the litter PS. The litter temperatures measured at 20 cm depth varied between 30 and 37 degrees C. Heat evaporated the dung water and the DM content of the composts produced staid above 50%. The amounts of compost produced per fattening pig were of 127 kg with the litter S and of 157 kg with the litter PS. Corresponding amounts of N in the composts were of 1.38 and 1.92 kg/pig, respectively. NH3 emission was lower from litter S than from litter PS but small increases of NH3 concentration until 50 ppm were observed during the work of aeration. Adding new litter decreased the emissions. NO emissions were only observed with the litter S, during the aeration period. Pig performance and carcass qualities were not affected by the litter mate.