The stress of transition from pasture to the feedlot environment creates unique and variable nutritional challenges. The factors that are used to assign a risk category for the likelihood of developing bovine respiratory disease include time in transit from their origin, which is likely to be highly correlated with the amount of time away from quality feed and water. A high risk of developing respiratory disease is likely to correlate well with the animals' suppressed appetite immediately after arrival. This article discusses 2 distinctive categories of feeder animals (high-risk calves and yearlings) and their nutritional needs.