In the last few years, new research in sow nutrition has provided evidence that the traditional feeding regimen of gestating sows needs revision. In particular, the change of amino acid requirements from early to late gestation and the energy deficit of young sows in late gestation indicate that phase feeding of pregnant sows may be advantageous. This paper will review recent sow nutrition research and suggest feeding strategies for sows. 

It was found that the recent results for amino acid and energy requirements of sows strongly support the need for parity-segregated phase feeding of pregnant sows. The phase feeding program should consist of two diets that satisfy the highest and lowest amino acid requirements and can be mixed in appropriate ratios to cover the intermediate amino acid needs. The feed amounts should be increased for the last four weeks of gestation. The increase in feed allowance of a corn-soybean meal diet should be 0.6 kg/d for gilts, 0.5 kg/d for 2nd parity sows and approximately 0.4 kg/d for older sows. Such a feeding program requires slightly less feed during gestation compared to single phase feeding but supplies amino acids and energy to the sows in the right amounts at the right time.