the actual fermentation can be done with any feed, it sort of "pre digests" the food so that nutrients are more readily available to the animals. It also provides them with essential bacteria for their guts so they can more effectively digest whatever they do eat. It SIGNIFICANTLY cuts down on smell/runny poops, and they seem to eat much less. I ferment for chickens, guineas, and now my brand new turkey poults. It takes a little time to get the system moving, but once you have it in place, not significantly more time to dish out feed and put it down. It reduces waste greatly, because it's fed wet, so no scratching it about. I use whole grains for my layers, the same feed ground for my cornish X and bought game bird feed (crumbles) for the turkeys and guineas, since they need a higher protien ratio. There's an excellent thread on it here https://www.backyardchickens.com/t/644300/fermenting-feed-for-meat-birds It's ridiculously long, but reading the first few pages will give you an idea. For the cliff notes there's a fabulous article here http://naturalchickenkeeping.blogspot.com/p/fermented-feed.html that goes in depth about the benefits and process.