IL13 and infection: For group B, compared with pre-infection, the level of IL-13 increased at 0–4 wpi, followed by a decline at 5–6 wpi, and then increased at 10 and 12 wpi, among which significant increases were detected at 3 and 12 wpi (p < 0.05), while significant decreases were detected at 5 and 6 wpi (p < 0.05).