The impact of using a mathematical model estimating real-time daily lysine requirements in a sustainable precision feeding program for growing pigs was investigated in two performance trials. Three treatments were tested in the first trial (60 pigs of 41.2±0.5 kg): a three-phase feeding program (3P) obtained by blending fixed proportions of feeds A (high nutrient concentration) and B (low nutrient concentration); and two daily-phase feeding programs in which the blended proportions of feeds A and B were adjusted daily to meet the estimated nutritional requirements of the group (MPG) or of each pig individually (MPI). The five treatments tested during second trial (70 pigs of 30.4±2.2) were a three-phase group-feeding program; against four individual daily-phase feeding programs in which the blending proportions of feeds A and B were updated daily to meet 110%, 100%, 90%, or 80% of the lysine requirements estimated using a mathematical model. Feeders identified each pig and delivered, in response to each animal request, a blend of feeds A and B containing the estimated concentration of lysine required by this pig this day according to the assigned trialal treatment. Feed intake was recorded automatically by the feeders, and the pigs were weighed weekly. These individual data was used to estimate the required concentration of lysine for each pig. Nitrogen excretion was calculated by the difference between intake and retention. In the first project, the MPG and MPI programs showed similar performance results than 3P feeding program. However, compared with the 3P, the MPI feeding program reduced (P<0.05) the standardized ileal digestible lysine intake by 27% and the estimated nitrogen excretion by 22%. In the second project, feeding pigs in a daily-basis program providing 110%, 100%, or 90% of the estimated individual lysine requirements also did not influence performance results in comparison with the 3P. However, feeding pigs individually with diets tailored to match 100% of nutrient requirements made it possible to reduce (P<0.05) digestible lysine intake by 26% and estimated nitrogen excretion by 30% relative to 3P. Precision feeding is an effective approach to make pig production more sustainable without compromising growth performance.