I had this issue too.
I had Rosters in a defined area 6x5 with enough grass at reach, it seem some went sleeping without eating first, got the Animal starvation message until they woke up and eat.
Also maybe related:
-When you go hunting a sleeping animal, sometime it will get up and go eat some grass, instead of attacking back.
Meaning they don't prioritise eating over sleeping, while pawns do it properly.
Sorry I can't provide my save as I sold all my chickens, will try to isolate the savegame if it occur again.
I had Rosters in a defined area 6x5 with enough grass at reach, it seem some went sleeping without eating first, got the Animal starvation message until they woke up and eat.
Also maybe related:
-When you go hunting a sleeping animal, sometime it will get up and go eat some grass, instead of attacking back.
Meaning they don't prioritise eating over sleeping, while pawns do it properly.
Sorry I can't provide my save as I sold all my chickens, will try to isolate the savegame if it occur again.