Adding a Quality Magnesium Supplement can Reduce the Threat of Grass Tetany

Mar 25, 2021

Tara Jo Bina
Countryside Feed Sales & Nutrition Professional
After a long winter, nothing marks the arrival of spring better than lush green grass. But as welcoming as a nice thick pasture can be, it can also spell danger for cattle in the form of grass tetany.
Grass tetany is a metabolic disorder that occurs when there’s a lack of magnesium (Mg) in an animal’s blood. With symptoms similar to milk fever, early signs include muscle tremors and irritability, and can expand to total loss of muscle control, coma and death if not detected and treated with a magnesium and calcium (Ca) solution in time. 

Fortunately, providing cattle with a high quality magnesium supplement can easily prevent grass tetany in the first place. We seasonally stock Beef Builder® 6% Green Pastures Hi Mag Non-Medicated at our Seneca location and Purina® RangeLand® Pro Mineral 6 Hi Mag at our Hillsboro location – both in 50 lb. bags. Although most cattle minerals have magnesium levels of 1 or 2 percent, these products contain at least 8 percent magnesium – helping ensure magnesium levels remain sufficient when the threat of grass tetany is elevated. 

Spring is when cattle are most at-risk of developing grass tetany, because cool-season grass pastures contain high levels of potassium (K) and nitrogen (N) at green-up. Each of these nutrients makes it harder for livestock to absorb magnesium, which is already limited in cool-season grasses as it is. The disorder can also present a problem in the fall, in newly seeded wheatgrass and ryegrass pastures.
Older cows are particularly susceptible to grass tetany – especially those that are lactating. Overly thin and fat cattle are also vulnerable, as are Angus cattle and their crosses. Other livestock, like sheep, goats and horses, can also develop the disease.
I encourage producers to begin offering a high magnesium mineral supplement to cattle about 2 to 3 weeks before turning them out to lush green pastures. Then continue to feed for another month or two after the first sign of grass growth.
Another great way to help prevent grass tetany is to put cattle on a good mineral program throughout the winter months. Doing so can reduce the need to provide a high-magnesium mineral supplement during green-up altogether.
Exactly what should that mineral package include? Every operation is different, so contact your local Countryside Feed nutritionist for assistance in selecting the best mineral products for your herd. You can always count on them to customize a program that helps achieve your productivity goals.

Read More News

Jan 24, 2023
Total digestible nutrients (TDN) are the common energy reference for both feed content and animal requirement, so how are the two connected and what can we know to better examine TDN of feedstuffs and use energy economically?
Jan 09, 2023
While it is true that carcass traits and beef product attributes are largely influenced by the genetic decisions of seedstock and commercial cow-calf producers and the feeding decisions of feedlot managers and nutritionists, the animal health decisions made by producers and veterinarians throughout the production chain also play a role. A number of studies have indicated that muscling, marbling, and tenderness all can be negatively impacted by cattle health problems. 
Dec 06, 2022
Although it's usually energy and protein intake thats emphasized when planning winter cow nutrition, ensuring adequate vitamin A intake is also important. Vitamin A is the vitamin most likely to be deficient in cattle diets and is the only vitamin with a well-defined requirement. It is important for vision, bone formation, growth, reproduction, and skin and other tissue health.

Related Topics