(1. College of Animal Science and Technology, Beijing University of Agriculture, Beijing 102206,China; 2. Key laboratory of universities in fujian province, Reproductive regulation and reproductive health, Xiamen university medical school, Xiamen 361102, China; 3.Research Institute of stomatology, Hospital of Stomatology, Sun Yat-Sen University, Guangzhou 510030, China;4.Animal husbandry and fishery extension station of Changping,Beijing 102200,China)
Q95-33