Thank you!I have around 70 chickens and a couple dz turkeys. I go through 4 five gallon buckets made with 2 gallons of dry feed. Depending on forage availability.
FF FAQ a byc member wrote up.
https://tikktok.wordpress.com/2014/04/13/fermented-feed-faq/
I believe it was a 1/4 teaspoon of RP per chicken.
There's a bunch of threads on RP, here's one with some links to studies
https://www.backyardchickens.com/threads/how-do-you-feed-your-chickens-red-pepper-flakes.1567625/