1. Department of Animal Science College of Coastal Agricultural Sciences Guangdong Ocean University Zhanjiang Guangdong Province P. R. China
2. Guangdong Academy of Agricultural Sciences Key Laboratory of Animal Nutrition and Feed Science (South China) of Ministry of Agriculture State Key Laboratory of Livestock and Poultry Breeding Guangdong Public Laboratory of Animal Breeding and Nutrition Institute of Animal Science Guangdong Key Laboratory of Animal Breeding and Nutrition Guangzhou P. R. China