Because layer feed is probably responsible for the early death of three of the roosters here. It's designed for chickens that lay eggs. It isn't designed for chicks, roosters, or hens past their prime who are not laying regularly.Why feeding layer pellets to a mixed sex flock? This thread is awesome!
I've provided a link to a thread started by Kris5902 that has more information rather than type out the problems I'm aware of.
https://www.backyardchickens.com/th...reeding-roosters.1282637/page-5#post-20708730
https://www.backyardchickens.com/threads/layer-feed-and-breeding-roosters.1282637/