This study had the following goals: I. To compare sow nursing behaviour in a sample of farms with group housing (GH) and individual housing (IH) systems for lactating sows with piglets. II. To quantify the variability in nursing behaviour attributable tobetween-farm differences. III. To document the decline in maternal nursing investment in GH and IH during the last two weeks before weaning.There was no significant difference between GH and IH farms in total number of nursings, in number of nutritive nursings or in proportion of nursings initiated by the sows. However on GH farms sows terminated higher proportion of nursings (p=0.05) and allowed piglets post-ejection massage for shorter time (p=0.02). Nursing synchronization was higher among sows on GH than on IH farms (p=0.006).