We've been fermenting whole oats for our animals for a while. The water swells the oats and definitely stretches out the feed which reduces the feed bill. Nutritionally, I can't think of anything better than what basically amounts to 'overnight oats' for animals. Of course, whole oats used to be cheap @ $8-10 a bag, now we pay about double but still cheaper, cleaner, and bettter for them than BlackTractorRock Supply bag o'poison laying feed.
Once we got pigs, we started mixing in BOSS (black oil sunflower seeds) for additional fiber and the oil helps keep their skin from getting flaky. Chickens, pigs, goats and one fat ass (donkey) absolutely LOVE soaked grains.
Now I source spent brewer's grain which has more protein than oats. I actually use the oats to cut down the protein under 20%.
Our animals are fat, happy, and productive while our feed costs are substantially lower than people with comparable amounts of eaters.
If y'all follow our farm IG page you'll see how I make the slop I feed them all. it's @meadow_creek_ranch on the Insta Gram