A questions about aphids

[swap]

We have six hens in a community garden and we have a large amount of kale and collards growing all around so there is no shortage of greens for the girls. But my questions is, some of the kale is infested with aphids but at the stage where it looks like they are producing what is sometimes called sooty mold. It looks all grey and mushy. Is this still okay to feed to the chickens?
thanks!