Prevent grass tetany in livestock |

Prevent grass tetany in livestock

Richard Snell
Barton County Extension Agent

Rye, wheat, and triticale are about ready to graze. These fields can be a great resource for livestock, but they can cause health problems.

Grass tetany is caused by low blood magnesium. Low blood magnesium can be due to low levels of magnesium in lush spring grass, but it also is caused by mineral imbalances like high potassium and nitrogen or low calcium in the diet.

Grass tetany primarily affects older, heavy milking cows or sheep, but young stock also can be affected. It occurs most frequently in spring during cool, cloudy, moist conditions when lush, immature grass starts growing rapidly.

Cattle or sheep affected by tetany often graze away from the herd, are irritable, show muscle twitching, awkwardness, and staggering, and are somewhat wide-eyed and staring. When severe, the animal will collapse, thrash around, throw its head back, lapse into a coma, and possibly die.

You can do several things to prevent grass tetany. First, wait until grass is four to six inches tall before grazing. Also, feed or graze legumes like clover or alfalfa when you start on pasture since they have high magnesium levels.

Adding about 10 to 20 grams per day of supplemental magnesium via commercial or homemade salt-mineral mixes is a good way to reduce tetany problems, but you should begin almost 30 days before grazing starts. Magnesium oxide is one of the best and cheapest sources of magnesium. Mix equal parts of magnesium oxide with di-calcium phosphate (di-cal), salt, and ground corn for a simple home-made supplement that provides adequate magnesium when cows eat about one pound of the mix per week.

As always, an ounce of prevention is worth a pound of cure.


Equine neurologic case investigation in Weld County


BROOMFIELD, Colo. — The Colorado Department of Agriculture State Veterinarian’s Office was recently notified of an equine neurologic case in Weld County. The State Veterinarian’s Office has been collaborating with the Colorado State University Veterinary…

See more


Start a dialogue, stay on topic and be civil.
If you don't follow the rules, your comment may be deleted.

User Legend: iconModerator iconTrusted User