Lanzhou Institute of Animal Science, CAAS, 730050, Lanzhou, Gansu, P R China;
Lanzhou Institute of Animal Science, CAAS, 730050, Lanzhou, Gansu, P R China;
Lanzhou Institute of Animal Science, CAAS, 730050, Lanzhou, Gansu, P R China;
Lanzhou Institute of Animal Science, CAAS, 730050, Lanzhou, Gansu, P R China;