This paper will review recent sow nutrition research and suggest feeding strategies for sows. Firstly, amino acid requirements in late gestation are greater than in early gestation. Threonine and isoleucine requirements increased, relative to lysine, from early to late gestation while the tryptophan to lysine ratio showed little change. The threonine to lysine ratio was greater for both early and late gestation in the third vs. second parity. These changes in amino acid requirement have important consequences. First, the magnitude of change in requirements makes it nearly impossible to satisfy the requirements using a single diet during gestation. Second, the data show that the amino acid ratios change as pregnancy progresses and as sows age. These changes in ideal amino acid ratios for sows are probably caused by the changing contributions of requirements for maintenance and maternal and fetal growth to total amino acid requirements. Secondly,  it can be expected that energy requirements increase as pregnancy progresses because of sow weight gain and because of the exponential growth of fetuses. Because of the changes in energy and amino acid requirements during gestation, a single phase feeding program will lead to overfeeding during early gestation and underfeeding during late gestation. Overfeeding in early gestation results in unwanted fat deposition, while underfeeding in late gestation leads to sows entering lactation in a severe catabolic state. Therefore, phase feeding gestating sows is necessary to supply nutrients in the right amount at the right time.