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Grass Tetany: Causes & Prevention

Springtime is here! The grass gets greener, and producers are excited to get their cows out on pasture, but as a producer, did you properly prepare your cows for that lush green grass? Death from grass tetany can occur very rapidly. Luckily, there is an inexpensive “insurance policy” to help prevent it. Magnesium!

Grass Tetany Causes

Grass Tetany Causes

Grass tetany occurs when magnesium becomes deficient in the cow. Grass is high in potassium, nitrogen, calcium, and phosphorus. When a cow starts consuming that lush grass, high in these nutrients, it interferes with magnesium absorption. Lactating cows also require an increased amount of magnesium. These factors during the spring, increase the risk for grass tetany in your herd.

How to Prevent?

Prevention starts with feeding a high magnesium mineral or mixing magnesium by hand into your mineral for three weeks before turnout and then continued until grass matures (usually about three weeks after turnout). The University of Nebraska-Lincoln recommends feeding about 10 to 20 grams of magnesium per day. 

Prevention is the best method to manage grass tetany. Contact your CPM nutrition advisor for more information and to get set up with magnesium before you send your herd to those green, lush pastures.

Written by Carly Steffensmeier,

Livestock Advisor