Activit{\'e} motrice des truies en groupes dans les diff{\'e}rents syst{\`e}mes de logement

Assessment of the motor activity of group-housed sows in commercial farms. The objective of this study was to specify the level of motor activity of pregnant sows housed in groups in different housing systems. Eleven commercial farms were selected for this study. Four housing systems were represented: small groups of five to seven sows (SG), free access stalls (FS) with exercise area, electronic sow feeder with a stable group (ESFsta) or a dynamic group (ESFdyn). Ten sows in mid-gestation were observed in each farm. The observations of motor activity were made for 6 hours at the first meal or at the start of the feeding sequence, two consecutive days and at regular intervals of 4 minutes. The results show that the motor activity of group-housed sows depends on the housing system. The activity is higher with the ESFdyn system (standing: 55.7%), sows are less active in the SG system (standing: 26.5%), and FS system is intermediate. The distance traveled by sows in ESF system is linked to a larger area available. Thus, sows travel an average of 362 m $\pm$ 167 m in the ESFdyn system with an average available surface of 446 m${}^2$ whereas sows in small groups travel 50 m $\pm$ 15 m for 15 m${}^2$ available.