Dog's don't generalize very easily. Think about training a basic behavior. The dog may have mastered "sit" in your living room, but it will still take a lot of effort to effectively train a "sit" in the backyard or out in public. More complex behaviors like agility have to be practiced in dozens of different locations before the dog realizes it's the same activity in a different spot. I don't see why coursing would be any different, although in coursing there's nothing to train, really--the dog just follows its instinct.