Cats and hawks eat the same diet in Nature.  Falconers are more obsessed
the health of their hunting companions than almost any other husbanders.
Like hawks, cats need fur, feathers, claws, guts, fecal bacteria and
other materials found only in whole small animals.

Falconers feed their charges (when they run out of game meat)whole frozen
quail that are produced for this purpose.  They cost about $1.00 each and
are available from several dealers on the web.  Adult feeder mice are
also available from pet dealers for about 50 cents each (frozen or
alive)in quanities of 100.

Ray Audette
Author "NeanderThin:A Caveman's Guide to Nutrition"
http://www.sofdesign.com/neander