This is a great site: http://www.nal.usda.gov/fnic/foodcomp/search/index.html
that was passed on to me from a Raw Pet Food Store that I used to buy from.
Type in your search words example: chicken raw, then under Food Groups choose: Poultry Prouducts. Next page pick the item that matches your search the closest, next page pick a weight amount, click Submit, next page will give you a full breakdown of everything in that item. It does consider bone for example as refuse so that amount wouldn't be included in the breakdown