Katie Hennessy

What is Grass Tetany in Cattle

Grass tetany is also known as hypomagnesaemia (or grass staggers), and is a magnesium (Mg) deficiency in cattle, primarily lactating cows. This deficiency can occur when there is a change in feeding from winter silage feed to rapidly growing spring grasses. The occurrence of grass tetany is greatly reduced after the forage matures. Only a small amount of Mg is stored in the body, therefore lactating cows require a constant supply of magnesium in their diets to supply the body with enough minerals to produce milk.[emember_protected custom_msg=”Click here and register now to read the rest of the article!”]
Symptoms of the disease are similar to milk fever or ketosis. Acute cases are often found dead but you may see clinical signs such as excitability, twitching, abnormal gait, vocalization, convulsions, weight loss, decreased appetite, ear flicking, frothing at the mouth, and decreased milk production. You should contact your veterinarian promptly when you observe any of these signs for treatment and diagnosis.
Some ways to prevent grass tetany are to provide magnesium supplements, monitor calcium and phosphorus levels in the cows (cows with low calcium will appear sluggish), get an analysis of your feed to make sure the mineral levels are adequate, or adjust fertilizer as needed for forage or soil. For liming, use dolomitic limestone, which contains natural magnesium or graze lactating dairy cows on legume pasture.
column by Dr. Katie Hennessy
BIO: Dr. Katie Hennessy graduated from the University of Illinois College of Veterinary Medicine in 2008 with a degree in large animal health and equine medicine. After completing an advanced internship and working as an Associate Veterinarian, she is currently practicing at Polk Equine, LLC. Her expertise ranges from small and exotic creatures to large animals, specializing in equine medicine.

Accessibility Toolbar