1. Key Laboratory of Chicken Genetics and Breeding, Ministry of Agriculture and Rural Affairs, Harbin, P. R. China
2. Key Laboratory of Animal Genetics, Breeding and Reproduction, Education Department, Harbin, Heilongjiang Province, P. R. China
3. College of Animal Science and Technology, Northeast Agricultural University, Harbin, P. R. China
4. Guangdong Wens Nanfang Poultry Breeding Co. Ltd, Xinxing, P. R. China