With the winters we have lately I rarely change my feed up, if it gets below freezing for more than a week then I will but honestly our winter it barely gets out of the 40s for longer than a month. I like the way my birds feel on it and they seem to grow pretty healthy and hold a good weight with itThe only feed I’ve ever seen above another is the 22% SS feed how much above idk exactly but I was lead on to it and fed it until I couldn’t.
You gotta feed what you can. The feed doesn’t necessarily make the bird of course different birds require different amounts but that’s on you too check em. During the late fall into winter I feed a bit heavy nowadays and up the corn. Theirs people that get crazy with it but 10/10 the bird makes the difference aslong as he has good care behind him.