1. College of Animal Science and Technology Yangzhou University P.R. China
2. Institute of Animal Science, Guangdong Academy of Agricultural Sciences, State Key Laboratory of Livestock and Poultry Breeding, Key Laboratory of Animal Nutrition and Feed Science in South China, Ministry of Agriculture and Rural Affairs Guangdong Provincial Key Laboratory of Animal Breeding and Nutrition Guangzhou P.R. China
3. Department of Animal Production, Faculty of Agriculture Cairo University Giza Egypt