Heat production by fattening pigs in deep-litter or conventional slatted floor systems.

The insulation and ventilation requirements for livestock buildings depend on the amount of heat and water vapour produced by the animals. Our knowled ge of heat production in slatted floor buildings must be adapted to the dee p-litter system, in which there is early composting of the slurry. We isola ted the effect of the husbandry system on heat and water vapour production using the same building, animals and external temperature. We compared the amount of heat and water vapour produced with the deep-litter system to tha t predicted by models, and to that of a conventional slatted floor system, used as a reference. Twelve pigs were fattened in two identical 14 m(2) ani mal enclosures, with natural ventilation, and with external and internal te mperatures kept constant(13 degrees C and 23 degrees C). The total, sensibl e and latent heat productions were measured for the deep-litter housing dur ing growing-finishing pigs and were equal to 302, 127 and 176 W, respective ly. The litter produced a large amount of heat, which led to the evaporatio n of approximately 4 kg of water vapour.pig(-1).d(-1). This made it possibl e to maintain the internal temperature because there was a small but notice able increase in sensible heat and significantly less heat loss through the floor. ((C) Elsevier/Inra).