There is a whole other thread on this. Whether one food holds up the digestion of another has not been proven by scientific research one way or the other. The thread is here: http://www.pets.ca/forum/showthread.php?t=72523
The only helpful thing I can add is to wonder why you would feed what seems to be two complete meals so close together anyway? Pooch gets supper in the evening and then a pre-bedtime snack of a raw chicken? A whole raw chicken? I can't help wondering why his supper doesn't hold him till breakfast? Does he get breakfast too?