Layer feed has more calcium than other feeds for chickens or ducks.Is it terrible to feed layer feed to roosters and drakes?
Offering it to males or to partly-grown birds is not terrible, but there is some chance of the calcium hurting them (damage to their kidneys if they eat it for weeks or months or years).
I think @rosemarythyme has given the best solution:Im rattling my brain on the best way to feed a mixed flock of chickens and ducks, various ages.
Make sure there is also a dish of oyster shell, so the laying females can get the extra calcium they need, and they should all be fine.All flock or flock raiser which is formulated for all poultry will be fine for chicks, ducklings, and adult birds of both genders.