1. College of Animal Science and Technology; China Agricultural University; Beijing China
2. Institute of Animal Husbandry and Veterinary Science; Shanghai Academy of Agricultural Science; Shanghai China
3. Department of Genomic Medicine; J. Craig Venter Institute; La Jolla CA USA
4. Equine Center; China Agricultural University; Beijing China
5. Key laboratory of Animal Breeding and Genetics of Ministry of Agriculture; P.R. China