Abstract
Research with many nutrients for growing swine has historically focused on the effects of supplementation levels on feed intake, growth, and feed conversion ratio. Following the establishment of nutrient requirement estimates for the maximization of, principally, growth rate, there certainly have been studies that have evaluated altered nutrient supplementation effects on a variety of metabolic responses related to health. However, often the value of increased nutrients for health improvement in a typical production setting is not fully realized because of the difference in the conditions that exist between a typical production setting and a university research setting coupled with a use of only a subset of animals in a university setting and the fact that the subset of animals that are used may not include the most health-susceptible portion of the population. Thus, research in many university settings will not capture the true effect of health challenges or of added supplementation on mortality and morbidity. Further, when decisions about nutrient supplementation levels are made on the farm, the decisions must consider the cost of the nutrient relative to the potential improvement in performance; this exercise determines the return on investment (ROI). Consequently, in situations where the effects of a nutrient on health are inadequately quantified or infrequently observed, the ROI for increased nutrient supplementation is underestimated. Examples from vitamin supplementation demonstrate the difference between the ROI when it is calculated only from growth performance compared to a calculation that includes both growth performance and mortality. The examples argue for a more robust ROI calculator that includes mortality. Additionally, the lack of knowledge of nutrient supplementation effects on the entire pig population, with specific knowledge of the most health-susceptible segment, argues for scaling up of promising results observed in a university setting to a commercial setting.