I wouldn't waste good meat on my chickens unless it was scrap or leftover. However, for your birds, I think raw is fine. A chicken is unlikely to suffer from mammalian parasites, bodies are too different. Just make sure it is fresh and good still when you offer it, rotting meat can be much more problematic for them.
Around my way you can kill an unlimited amout of doe, and i already have 3 in the freezer any more meet now would just be donated to the supply kitchens for the homeless. So I figured I would just feed it to my chickens instead.