A popular belief exists that animal agriculture competes for human food supplies and wastes resources. Little scientific information exists regarding this concept, and it is therefore necessary to quantify human-inedible feedstuff use and re-examine the feed efficiency concept using a ratio of human-edible feedstuff input to human-edible (animal protein) output. This paper (IP 53) addresses the commonly heard argument that livestock compete with humans for food resources, thus providing support for the continued existence of livestock production. It also addresses the knowledge gap that currently exists as to the quantity of human feed and fiber by-products used within animal agriculture.