维生素缺乏症的原因是多种多样的，但是相当重要的是不充足的饲料采食量（管理原因），这很难避免维生素摄入不充足。
The reasons why vitamin deficiencies arise are many and varied but not leastdue to an inadequate feed intake (for management reasons) which is inextricablylinked to inadequate vitamin intake.
维生素缺乏症的原因是多种多样的，但是相当重要的是不充足的饲料采食量（管理原因），这很难避免维生素摄入不充足。
The reasons why vitamin deficiencies arise are many and varied but not leastdue to an inadequate feed intake (for management reasons) which is inextricablylinked to inadequate vitamin intake.
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