Influence of the use of partially slatted floors and pen size on air quality during the growingfattening period

Three rooms were compared : a control room, with a totally slatted concrete floor (six pens of ten pigs), a second room, with a partially slatted concrete floor (six pens of eight pigs) and a third room, with a partially slatted concrete floor (two pens of twenty-four pigs). In the control room the surface per pig was 0.70 m2 vs. 0.85 m2 for the other two rooms. In the partially slatted floor pens, 50 % of the surface area was slatted. During two periods, one in spring (April to June) and the other in winter (October to December), ammonia concentrations, production of ammonia and odours were measured every 15 d between when the pigs entered the room and when the first pig was slaughtered, 90 d later. Floor type affected ammonia concentrations in the pig unit, ammonia in the extracted air and odour production whatever the size of the pen (partially slatted > control). The hypothesis that there is a relationship between the surface area of slurry exposed to the air and the emission of ammonia was not confirmed. The depth of slurry and the ventilation system appear to greatly influence ammonia production in the partially slatted floor rooms. Odour emissions were multiplied by twofold in the partially slatted floor rooms compared to the control room. This appeared to be linked to the cleanness of the pigs and the solid part of the floor, which was implicated in the production of odours rather than ammonia.