score:3
Etihad states that they interline baggage with Turkish Airlines, among many others, so as long as you are on a single booking, your baggage will be transferred for you. You will not need to go through immigration or recheck your bags at AUH.
Upvote:2
The general rule is that you can expect your luggage to be checked in all the way if:
1) Same airline, same booking OR
2) Different airlines, same booking OR
3) Same airline, different bookings
To allay doubts, just call the airline(s).