1. National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics and Breeding of the Ministry of Agriculture, Beijing Key Laboratory for Animal Genetic Improvement, College of Animal Science and Technology, China Agricultural University, Beijing, China
2. Animal Genetic Resources Group, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
3. State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
4. Tianjin Institute of Animal Sciences, Tianjin, China
5. College of Biological Sciences, China Agricultural University, Beijing, China