1. College of Animal Science and Technology, Hunan Agricultural University, Changsha 410128, China
2. College of Animal Science and Technology, Southwest University, Chongqing 400715, China
3. College of Veterinary Medicine, Southwest University, Chongqing 400715, China
4. Animal Breeding and Genetics Key Laboratory of Sichuan Province, Sichuan Animal Science Academy, Chengdu 610066, China