Thanks again for responses, all very good!
Not to mislead anyone, my dog WAS PUNISHED.
I not only smacked him more than a few times, I also used a technique demonstrated by Cesar Milan...imitate a dog bite with your hand on your dog's throat. At the same time, and as I have always said, I yelled, "NO! Chickens!" I yell this every time my dogs are near the run and are focused or too interested in the birds.
I also immediately followed this by grabbing him by the scruff of his neck (another discipline Cesar Milan has mentioned) and walked him pretty roughly back to his run...about 1/6th of a mile. He got an earful the whole way back. I put him into his travel size kennel, closed the door, covered it with a blanket, and left him in it for 30 minutes. Some people won't use the kennel as punishment, but, I do. It is a good way to confine him.
Anyway, I feel he was adequately punished...as I said earlier...short of beating the crap out of him. He did get a pretty good whupping.
I again thank you all for your responses. I'm still mad at the dog, but, again...he is a predator...training or not. Be careful folks!