I don't think so, could be feet, or beaks, or any other part that wouldn't go into the human food chain,If its a good part of the bird they would advertise it, that's why my main feeding is Beef, Chicken and rabbit, proper stuff.
not looking for an argument, but try contacting them and asking what part of the bird they use, you may be lucky to recieve an answer.
but if your happy, and your dogs do well on it, well carry on.
No me neither CJ I think its down to what grade of chicken ie human consumption,pet food or below