Beef producers in Northeastern Pennsylvania should have some knowledge about grass tetany in beef cattle.

 — Beef producers in Northeastern Pennsylvania should have some knowledge about grass tetany in beef cattle.

Grass tetany can be a serious, often fatal metabolic disorder characterized by low levels of magnesium in the blood serum of beef cattle. Grass tetany primarily affects older beef cows, but, it may also be a problem in young beef cattle and dry beef cows.

Grass tetany happens most frequently when beef cattle are grazing pastures that contain very succulent, immature grasses. This risk increases when pastures have been fertilized with nitrogen sources such as urea. A typical “high risk” for grass tetany occurs in the spring time, often following a cool period (temperatures between 450F and 600F) when pasture grasses are growing very rapidly.

Some of the symptoms of grass tetany include: stumbling and staggering, muscle trembles, muscle twitches, excitability and usually convulsions, coma and death.

The easiest way to prevent grass tetany problems, in a beef cattle herd, is to start and supplement beef cows on a magnesium mineral supplement prior to these cattle gaining access to spring pasture for grazing.

The typical magnesium supplement is magnesium oxide. In order to increase the palatability of magnesium oxide, a variety of supplement “carriers” need to be considered. These include: dried distillers grains, dried molasses, wheat midds and soybean hulls.

Typically, susceptible, older beef cows need to be consuming at least 4 ounces of magnesium supplementation every day. The daily supplementation will increase blood magnesium levels and can help to alleviate grass tetany risks in a mature beef cow herd.

Other strategies to consider to lower the risk of grass tetany include: grazing less susceptible beef animals on higher risk pastures. This would include: beef steers, heifers, dry cows and beef cows that have calves over (4) months of age, at their side. Pastures that contain certain legumes, such as alfalfa and/or clover will decrease the incidence of grass tetany in grazing beef cattle.

The peak season for grass tetany problems, in beef cattle herds, is April thru early May. Once again, area beef cattle producers are encouraged to be aware of the potential problem associated with grass tetany in beef cattle herds.

For additional information about “Grass Tetany In Beef Cattle”, please contact the Wayne County Cooperative Extension at: phone 1-570-253-5970 extension 4110, or, by email at: (Ed Pruss).

To register, for more information, contact Penn State Extension, 648 Park Street, Honesdale, PA, 18431call 570-253-5970 ext. 4110, or e-mail

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