(grass staggers, magnesium deficiency)
Grass tetany is a complex disease traditionally associated with a magnesium deficiency. All ruminants are susceptible. Magnesium deficiency in sheep most commonly occurs in acute form within 4-6 weeks of lambing. Affected ewes exhibit sensitivity to touch and trembling of the facial muscles; some are unable to move, others move stiffly; extreme cases collapse and show repeated tetanic spasms with all four limbs rigidly extended.
Low blood magnesium can be caused by low levels of magnesium in lush spring grass or by mineral imbalances such as high potassium and nitrogen or low calcium in the diet. Ewes with grass staggers are often low in calcium as well as magnesium. It is therefore wise to use a combined treatment of calcium borogluconate and magnesium hypophosphite. Producers can add about 10 to 20 grams of commercial or homemade supplemental magnesium to livestock diets to prevent grass tetany. Magnesium oxide is one of the best and cheapest magnesium sources.