The take home message for producers and farm managers is that they should be aware of these issues and relationships and understand the effects on their own animals and farm units. DSM Nutritional Products have developed the Optimum Vitamin Nutrition concept, aimed at providing commercial nutritionists and nutritional advisers to home mixers with effective tools and guidelines for high precision formulation. The next two articles in this series will discuss specific vitamin values for pigs as well as the formulation of working diets.