In the recent years, the reproductive performance of sows has been drastically improved. Nowadays, in many farms, with the use of hyperprolific sows, the average litter size exceeds 13 piglets at farrowing and 11.5 at weaning. These changes in performance have had major effects on nutritional requirements during both pregnancy and lactation. At the same time, from the results obtained in the last twenty years on energy, amino acid and minerals utilisation in sows, it has become possible to improve the determination of nutrients requirements (factorial approach) and the prediction of animal's response to nutrients supplies (modelling). The aim of the present paper is to describe how the current state of knowledge on sow nutrition can be included in an integrated model, as well as in a software tool, designed for end-users, mainly nutritionists in the pig industry and students in animal nutrition. The use of the decision support tool is illustrated through some examples. It allows to determine energy, amino acids and minerals requirements of sows according to production objectives, or to predict body composition changes for a given feeding strategy.