Livestock feed demand is a collection of derived feed demands by various livestock categories. A structural understanding of demand for feed grains and total concentrates requires knowledge of separate feed demand relationships for each major livestock category. While a number of aggregate livestock feed demand relationships have been estimated, little is known about the structure of feed demand by livestock type. In this study unique livestock feed demand relationships for feed grains and total concentrates are estimated for each of seven major livestock categories. The estimated relationships show substantial differences in elasticities of concentrate and feed grain feed demand with respect to livestock price across livestock groups. Using feed demand parameters by livestock category enables analysts to evaluate policy effects of changes in feed demand quantities and feed costs within the livestock economy, as well as to provide more reliable estimates of the total change in feed demand.