1. Department of Poultry Science, Chongqing Academy of Animal Science, Chongqing, P. R. China
2. Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, P. R. China
3. Chongqing Engineering Research Center of Goose Genetic Improvement, Chongqing, P. R. China
4. Animal Husbandry and Veterinary Station, Sucheng District Suqian, Jiangsu, P. R. China