Simulations of precision feeding (PF) in which gestating sows were individually fed a daily mixture of two diets with different amino acid contents indicated a reduction in protein intake, feed costs, and environmental losses compared to sows fed a conventional single diet (CF). These results have not been verified on farm. Thus, the objective of the present study was to compare the effect of this PF strategy on productive and reproductive performances of gestating sows compared to the CF strategy. As the effects of such a strategy has not been reported yet on sows' feeding behavior (frequency of visits and time spent in the feeder), it constituted the second objective of this study. The experiment included 131 gestating sows divided into the two feeding strategies regarding their parity and body weight at insemination. Feed supply was similar for the two strategies. The results matched those from simulations as sows fed the PF strategy reduced their lysine ingestion of around 25%, which therefore reduced nitrogen excretion of 18.5%, and feed costs by 3.4 euros per gestation or 8 euros per ton of feed. Phosphorus intake and excretion were also reduced with PF compared to CF (around 8% and 9%, respectively). Reproductive performance, defined as the number of piglets per litter and the litter weight, was not affected by the feeding strategy. All sows usually ate their daily ration in one "feeding visit." The PF sows did a constant number of "non-feeding visits" to the feeder during gestation (on average 4.25 visits/ d), while the CF sows did more non-feeding visits at the beginning of the gestation (on average 4.42 visits/d) and less at the end of the gestation (on average 3.69 visits/d) than the PF sows (P < 0.01). The sows spent 54% of their daily time in the feeder for feeding visits, and 46% for nonfeeding visits. The PF sows spent more daily time for non-feeding visits than CF sows (32.4 vs. 29.7 min/d, respectively, P < 0.01). Time spent at the feeder for feeding visits or non-feeding visits was constant over the gestation for the CF sows (35.3 and 29.2 min/d, respectively) while for the PF sows it increased over gestation. In conclusion, the PF strategy can be used to reduce lysine intake without influencing reproductive performance while reducing protein intake and feed costs. Feeding behaviors were barely affected by the feeding strategies but may serve as management indicators to detect sick or injured animals.