Hi! Needing advice for my rooster. He is a year and a half old. Today we noticed he wasn't himself. He is not holding his head high and isn't crowing. He is eating and drinking. But I found him in a nest box laying down this evening. When he heard others come in coop he got up and jumped on roost. So he's not completely lethargic but not his usual energy. He moves very slow compared to his usual. We've dealt with sour crop and impaction with other chickens in the past but his crop feels ok. Any clues ?