Key Laboratory of Agricultural Animal Genetics;
Breeding and Reproduction of Ministry of Education;
Huazhong Agricultural University;
Wuhan 430070;
P.R.China;
Laboratory of Sheep and Goat Genetics;
Breeding and Reproduction;
College of Animal Science and Technology;
Huazhong Agricultural University;
Wuhan 430070;
P.R.China;
immunocastration; reversibility; safety; animal welfare; DNA vaccine;