[en] Feeding gestating sows with high fibre diets (HFD) helps induce satiety without excessive energy intake. Neutral Detergent Fibre (NDF) (15-20%) enables sows to adapt their feed intake to their needs. Therefore, ad libitum feeding becomes possible, reducing the costs of feeding equipment. Fibre effect on the feeling of satiety is due among others to the higher amount of feed intake, the increase of eating time and delay in gastric emptying. Sow welfare improvement due to the feeling of satiety has for consequence a reduction in the occurrence of stereotypes and aggressions. The disadvantage of HFD feeding is linked to a reduction of cell component accessibility to digestive and microbial enzymes. However, energy efficiency of fibre degradation is better for sows than for growing pigs. If the amount of feed offered takes into account the reduction in energy digestibility, sow performance is not affected. Besides, the increased capacity of the digestive tract may result in an increased capacity of the digestive tract may result in an increased feed intake during early lactation, supporting higher milk production and limiting the body reserve mobilisation. On the environmental level, increasing fibre content reduces ammonia emissions but increases methane emissions.