2.1. Bovine Intestinal Epithelial Cell Culture

BIECs were obtained from the Institute of Animal Culture Collection and Development at Yangzhou University in China. The establishment was based on previous studies [22]. BIECs were cultured in DMEM/F12 media (Gibco, Grand Island, NY, USA) along with 10% foetal bovine serum (Gibco, Grand Island, NY, USA) and antibiotics (100 U/mL penicillin and 100 μg/mL streptomycin) (Sigma-Aldrich, Shanghai, China) and kept at 37 °C with 5% CO₂.