TY - China Feed A1 - T1 - Y1 - 2021-11-20 JF - China Feed JO - China Feed SP - 39 EP - 42 VL - 1 IS - 22 UR - http://journal.chinafeed.com.cn N1 - 10.15906/j.cnki.cn11-2975/s.20212211 ER -