I am doing research for a direct mail letter on the appalling fact that the school lunch program is sold a large amount of chicken from used up egg laying hens, which is also traditionally used in dog food and compost. I came across a gem of a paper called RUNNING HEAD: Spent Hen Meal for Layers, which basically investigates the question, can you feed your dead garbage chickens to your live chickens? Answer: Yes.
Conclusions: Nutritionally valuable high-protein meals can be
produced from whole spent hens using conventional rendering
procedures. Such meals may be safely used at levels up to 10%
in diets for laying hens provided good analytical procedures are
followed to determine nutritional content. Due to the high level
of residual fat and the highly unsaturated nature of this fat, it will
be necessary to insure that adequate amounts of a suitable
antioxidant is used during manufacturing to prevent rancidity
No more chicken for me, thanks.