The science of animal nutrition has made significant advances in the past century. In looking back at the discoveries of the 20th century, we can appreciate the tremendous impact that animal nutrition has had on our lives. From the discovery of vitamins and the sweeping shift in the use of oilseeds to replace animal products as dietary protein sources for animals during the war times of the 1900s-to our integral understanding of nutrients as regulators of gene expression today-animal nutrition has been the cornerstone for scientific advances in many areas. At the milestone of their 70th year of service to the nation, the National Research Council's (NRC) Committee on Animal Nutrition (CAN) sought to gain a better understanding of the magnitude of recent discoveries and directions in animal nutrition for the new century we are embarking upon. With financial support from the NRC, the committee was able to organize and host a symposium that featured scientists from many backgrounds who were asked to share their ideas about the potential of animal nutrition to address current problems and future challenges.