One of my friends has a 2.5. to 3 month old mixed puppy....German Shepherd, Golden Retriever, and Labrador Retriever. They have some chickens they are trying to raise on their farm. I guess the pup has killed two of them already.
Is there a way to train a dog NOT to do this, or is always instinct and you never can really train them out of it.
You can absolutely train a dog not to kill chickens if they are a part of your life. Correct them for the behavior of paying too much attention to them and keep them tethered or leashed until they are reliable enough to respond to voice commands.
I know that Melissa (Dostaff) has a lot of chickens and plenty of labs too. PM her for more advice.