Hi Dr. Dale,
Congrats on getting some gorgeous pups. Beautiful babies.
I don't think you're going to have to do any training of your pups to show them how to protect the chickens. Great Pyrenees are one of the few breeds developed as livestock guardian dogs, so as long as they are brought up with the chickens, they will have the desire to guard them, (just as they will have the desire to guard you and your family!) They are like maremmas, which are used quite a lot here in Australia, mainly to guard sheep, but also chooks and other flocks animals as well.
You will surely need to train them in other ways though, as you have said above...heel, come, etc..
Here's a good page of info. I found about them:
https://www.nationalpyr.org/know-the-breed
The following is a story you might be interested in. I really love this, and it's one of the reasons I've always had so much time for Aust Zoo and what they do. Besides having a massive and extremely well-run zoo, they give back a huge amount to the animal world in many ways. (They also have the biggest wildlife hospital in the world).
As for this story, Australia Zoo (Wildlife Warriors) is a partner in a program that protects cheetahs in Africa by protecting cattle. Instead of the cheetahs being killed by tribesmen for killing cattle, they are kept away from the cattle by Anatolian Shepherds, (another type of livestock guardian dog).
"Threatened by conflict with livestock farmers, Wildlife Warriors in partnership with Cheetah Outreach are working to protect the last stronghold of cheetah in Southern Africa. With less than 7,000 cheetah left in the wild, it’s never been more important to ensure the species is protected. By supporting Cheetah Outreach’s Anatolian Shepherd Dog Program, Wildlife Warriors are helping to provide farmers with a non-lethal method of managing these predators and promoting peaceful co-existence with cheetah."
There's a bit more about it on this site:
http://www.australiazoo.com.au/about-us/zoo-gossip/index.php?gossip=1366