Yes, if not treated right away.

Grass tetany is an anti-quality factor and a metabolic disease where livestock experience a severe case of magnesium deficiency while on spring pasture. Also known as hypomagnesemic tetany, grass staggers, winter tetany or wheat pature poisoning, it primarily affects older lactating cows that are 2 months into their lactation period (or suckling 2-month old calves) but can also affect young or dry cows and growing calves.

Grass tetany primarily occurs while grass is in its vegetative stage (or succulent immature grass) and after a pasture had been fertilized with lots of nitrogen. Nitrogen will decrease availability of magnesium to cattle, especially with potassium-rich soils, causing a significant decrease in magnesium in the blood serum of cattle.

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Grass tetany

Tetany is the medical term continuous spasm of muscles; tetany may result from hypocalcemia.

Hi,

Tetany is caused by a lack of calcium or vitamin d-3. To prevent Tetany, dusting crickets with a vitamin d-3 mix every week for adults and every other day for youngsters will do the trick.