The other thing you might do is locate an organic farm/hatchery or dairy in your area and see whether you can buy feed from them. Some of them may be willing to sell to you, or may be able to steer you towards a local producer of organic feeds, and that may - MAY - be cheaper than having it shipped long distances, etc. That's working out for me. There are other manufacturers - try googling organic chicken feed.
Of course, with only 8 chickens, 50 pounds of feed will last a long time, so it may not be such an issue. Good for you for taking the trouble, and good luck.!