Cows on pasture could be cows in trouble. As grass grows, it picks up many nutrients from the soil and can pass on many problems to cattle that eat it. One problem grazing cattle can pick up from pastures is grass tetany. Cattle affected are usually grazing cool-season grasses in cool, wet weather on soils with high levels of potassium and nitrogen. Grass tetany usually appears in cows with nursing calves and also can occur when cows are just consuming new pasture growth.

Grass tetany is a disease caused by low levels of magnesium in the blood of cattle. Characteristics of the disease include a stiff gait, paddling, falling down, convulsions and death. It occurs rapidly in cattle that appeared fine shortly before its onset. Treatment must be done quickly and includes giving magnesium and calcium intravenously to the affected cow.

You can prevent grass tetany by avoiding grazing in the types of pastures listed above and by supplementing magnesium.

A magnesium level of 20 grams per day is recommended to avoid grass tetany.