regrowing feathers please read?

[pine top]

this my have been asked before but here i go i bought 6 hens / 1 rooster anconas 10 mounths ago and have 2 hens that have not regrown there feathers (there wings were cut so no flaying) all the rest have new feathers and i dont think there laying now i have given all of them dry cat food for extra protine have wromed with poor on ivamic no mites there 2 1/2 year old 99% sure and thay have molted but for some reson these 2 are way be hind the others theres got to be somthing thay need that there not getting from me and i just dont know what it is i have owend chickens for years and have never had a problem that i could not figer out but this ones got me .
there stool is good there eating is great thout maybe rooster was being ruff on them took him out 2 mounths ago and is still out no improvment maybe someone can help . thanksYourLinkGoesHere