Welmin High Mag 20 is an economic 20% magnesium block in a highly palatable molassed base. The higher magnesium levels together with the essential trace elements will provide the beef and dairy cow with a source of magnesium which will further help reduce the risk of grass tetany especially when grass supply is plentiful and intakes of mineral may be reduced. Suckler cows are most at risk to tetany in the autumn due to the stresses at weaning.