Incidence of growing pig housing conditions, fully slatted floor or straw bedding, on technical efficiency

Poster. Two housing systems (fully slatted floor vs straw litter) were assessed with respect to their technical efficiency through an experiment using two batches of 72 pigs over the 30-115 kg bodyweight range. The comparison was carried out under two contrasting seasons, in order to take into account the usually reported difficulty in the climate control of straw bedding systems in cold conditions. Space allowance was respectively 1.25m2 per pig on straw and 0.75m2 on slatted floor. Pigs were offered the same feeds ad libitum. Dietary net energy level was 9.5 MJ and digestible lysine/net energy ratio were 0.9 and 0.8 g/MJ in growing or finishing periods, respectively. As expected, ambient temperature was reduced in the straw based system (by 2.7°C and 5.0°C on average in summer and winter, respectively) but this drop didn’t exceed the 6°C usually considered as the “gain” brought by the litter with respect to the thermal comfort of animals. Whatever the season, the straw based system induced a sharp decrease of average daily gain (-8%), mainly explained by a decreased feed efficiency (-7%). Regarding the carcass value, lean meat percentage and carcass yield were also reduced within the straw based system, as far as backfat and loin thickness were both negatively affected.