To all that feel it is fine to feed layer feed to Roos, younger birds, etc....-
We manufacture and sell about 3000 bags of layer feed daily, so, we have a fairly large sample size. I can tell you with absolute certainty, feeding layer feed to birds that aren’t laying, is not good for them. Hypercalcimia can have your chickens suffering through things that you can’t see. It can cause gout, rickets, kidney issues, etc.. Feeding layer diets won’t always kill your birds, but it certainly can. Most times they will survive just fine, but they will probably suffer through health issues that you don’t know about. (Young birds are much more likely to die on a layer diet, than an adult)
Your chicken may seem fine, but you can’t ask your chicken if they have sore bones, or kidney pain. You can’t ask them if they are constipated, or if they are depressed, chronically tired, or confused.
We have seen the issues time after time. We have also seen necropsy results on numerous birds that have been fed layer feed while not producing eggs. It is most certainly NOT good for them.