As spring approaches and grass begins to grow, grazing livestock may experience a forage-related problem known as grass tetany, grass staggers, lactation tetany, or hypomagnesemia. Grass tetany is a metabolic disorder caused by reduced magnesium (Mg) levels in the animal’s blood. In cattle, it generally affects older, lactating cows but can also be seen in dry cows, young cows, and in rare cases, growing calves. Symptoms often observed include nervousness, lack of coordination, muscular spasms, staggering, convulsions, coma, milk yield decrease, and death.