Prevention and Treatment: Grass Tetany

Lush, green, rapidly growing grasses present a considerable risk for grass tetany, regardless of season. The combination of high potassium and low magnesium and calcium in these forages is thought to be the primary cause of grass tetany. Because of the increased forage production and growth rate, cattle grazing fertilized pastures are generally at higher risk. The principal factor that influences concentration and availability of magnesium to both the plant and the animal is potassium. High concentrations of potassium negatively affect soil magnesium uptake by plants. High nitrogen concentrations following fertilizer applications also may limit magnesium availability