[en] Two identical rooms were arranged to house fattening pigs on a fully-slatted floor in one and on a straw-based deep litter in the other one. Each room was ventilated with an exhausted fan and the ventilation rates were adapted to have the same temperatures in the two rooms. Six successive batches of 16 pigs per pen were raised. The slurry pit was emptied and the litter removed after each fattening period. The mean daily weight gains of the pigs raised on slatted floor and on deep litter were of 742 and 729 g/day, the food conversion ratios 3.0 and 3.1 kg/kg, the lean meat percentages 59.8 and 60.0 % and the prices at slaughter 1.06 and 1.04 E/kg live weight, respectively. None of the differences was statistically significant. The amounts of slurry and manure produced were 290 and 187 kg per fattening pig, corresponding to 3.04 and 2.06 kg nitrogen per fattening pig, respectively. These differences were significant.