1 Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi 712100, China.
2 Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi 712100, China; Key Laboratory of Livestock Biology, Northwest A&F University, Yangling, Shaanxi 712100, China.
3 Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi 712100, China; Key Laboratory of Livestock Biology, Northwest A&F University, Yangling, Shaanxi 712100, China. Electronic address: yujiang@nwafu.edu.cn.
4 Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi 712100, China. Electronic address: dangruihua@nwsuaf.edu.cn.