I actually feed my herd 58% magnesium oxide from the local feed store. It is a 50 pound bag and cost me $35.00. It lasts me at least a year for 3 equines. You might try calling around to local feed stores and asking if they carry it, or could order it for you.
Also, Uckele has some you can purchase online as well.
Primary Response Team
September 2018, Summerfield, FL
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