Sows and vitamins: beyond empiricism.

Information on vitamins in reproducing sows is often lacking and has become outdated during recent decades, a period during which reproductive performances were influenced by considerable genetic improvements and changes in husbandry practices. Also, the information available is heterogeneous among vitamins. Therefore, empiricism has been and is still present in this field as illustrated by the large variations in recommendations among private or public institutions. Estimations of requirements for vitamins need to be brought up to date, beyond the prevention of deficiencies (practically absent nowadays), including the determination of optimal dietary levels for reproductive performance. This is a challenge for the future which is all the more important because criteria for reproductive performance are continuously evolving from prolificacy alone to other aspects such as survival and disease resistance in piglets. The roles of some vitamins in immunology of reproduction, antioxidative capacity and immune competency may eventually contribute to the improvement of these new criteria for reproductive performance. Moreover, although often forgotten, a collateral but not negligible aspect is the public's perception of dietary supplements of vitamins, which is excellent.