I don't ferment and I have no problem with my girls eating all of it or getting enough nutrition. I just add a little water and mix each morning when I give them their feed. You need to feed more at first until you figure out how much they need to eat. Once there is a little left each morning...
I've got 15 chickens and 4 ducks. Two chickens are bantams tho so they basically count as one so 18 birds. I did a 5 gal prob 1/2 full. After three days it smelt strong and the next morning it was foul. Overnight it got a bacterial bloom covering the entire top. It was enough to make someone...
See I had the one I fermented in or insulated garage and I think it was just warm enough to be too hot for it. Might have to go pick up a smaller bucket and do smaller amounts of feed. Or find a few large glass jars and do a days worth at a time.
I would just give volume wise the same amount you were before and if they eat it all and seem hungry in the evening feed a little more. Typically they don't eat as much fermented as non fermented because it's more readily digestible but I don't have a lot of experience with fermenting scratch...
I don't know what went wrong but the first week I had scratch and peck I tried fermenting it. Omg did it turn into the most disgusting horrid vomit worthy soup of awful. I threw out the spoon I was using to stir it with it was so bad. It went bad in only 4 days and it was pretty much overnight...