1. College of Animal Science and Technology, Hebei Agricultural University, Baoding, Hebei, China
2. School of Basic Medical Science, Hebei Medical University, Shijiazhuang, Hebei, China
3. Beijing Advanced Innovation Center for Genomics, College of Life Sciences, Peking University, Beijing, China
4. College of Animal Science and Technology, Hebei Agricultural University, Baoding, Hebei, China;, Email: Lxyun@hebau.edu.cn