Accumulation into one source of what is known regarding the feeding value of these materials and systems which have been developed for improving their digestibility, palatability or methods of handling was the motivation for organising this book. These has been an effort to include the major categories of unconventional materials which can potentially be upgraded to provide the ruminant with needed nutrients, but certainly some have been missed. It is hoped that this treatise will prove to be a valuable tool for workers involved in improving the utilization of residues and waste products for animals.