Facial expressions can reflect an animal's emotional responses to disturbances in its physical environment. This study involved 12 Large White sows, each reared in two different conditions during 2 successive farrowings and lactations, in a crate (CB) at third parity and then in a pen (CL) at fourth parity ; they had experienced each condition at the previous parities. In each condition, their reactions to highly predictable (feeding) and unpredictable but known events (iron injection, weaning) were measured by 2 methods for image production, facial images (N=240 CB and 210 images in CL taken) with a digital camera by a single operator before/after each event, and image extraction from video records to cover the +/-10 min period around 2 to 3 feeding events per sow (N=2090 in CB and 2325 in CL at ~18 d after entrance). Each image was annotated by a single observer. Uni-trait binomial logistic models correcting for the random effect of the sow were applied to explain head position, ear orientation, eye and mouth opening, and the presence of tears and drooling. Compared with crate, sows in the free condition had their heads up (image: 72.9% vs. 65.2%), their ears flapped (left ear: image 44.0% vs. 14.9% / video 26.2% vs. 22.4%, P=0.02), and more marked symmetry of the ears (video: 70.2% vs. 54.5%; P=0.0001) and eyes (95.5% vs. 89.1%; P=0.002); they were actively anticipating meals and showed a decrease in attention afterwards. In the blocked condition, the sows showed signs of increased vigilance, such as ears pricked up in various situations (image: 75.6% vs 46.1%) or backwards at mealtime (34% vs 22%) and eyes more open (image: 55.7% vs 31.9% P<0.001) and much more drooling before meals. A multivariate analysis to integrate the different facial features into the different responses and better characterise sow variation is currently underway. Facial expressions can be used to decipher the emotional state and mood of sows.