What Treats Reinforce Good Behaviors In A Dog

When we go for walks, Truffles could care less about treats and wants to sniff the bushes. I'm going to have to do a treat test so I know what he will eat too reinforce his good Behaviors while on walks.
Basically. what I will do is put out several treats while the dog is in a different room. Then let him out and see what treat he like best. That treat will be my reinforcing treat for good behavior only when on walks.