That happened to a friend here locally. She changed feeds and the hens were back to normal. She compared feed tags on the bad feed and the same brand feed she'd bought before the change - same ingredients, different order, so less nutritionally dense. She said they ate more of it, but laid far less.
One of the chicken feeds changed its formula and has been found to cause hens from laying. Hope yours eat as much good scrap as possible!
That happened to a friend here locally. She changed feeds and the hens were back to normal. She compared feed tags on the bad feed and the same brand feed she'd bought before the change - same ingredients, different order, so less nutritionally dense. She said they ate more of it, but laid far less.