News

As spring pastures begin to green up, the promise of lush forage comes with a hidden risk: grass tetany. This potentially fatal condition is one of the most serious cattle health concerns of the season—but the good news is, it’s preventable with the right nutrition strategy.

What Is Grass Tetany?

Grass tetany is a metabolic disorder caused by low levels of magnesium in a cow’s bloodstream. Symptoms can range from muscle tremors and irritability to severe outcomes such as coma or death. While low magnesium levels in forage contribute to the problem, spring grass is especially tricky—its high potassium and nitrogen content can actually reduce magnesium absorption in cattle.

This makes early spring a perfect storm for tetany. Cloudy skies, cool soils, and the fast growth of cool-season grasses—especially those in highly fertilized pastures—can spike your herd’s risk. Older cows and those in peak lactation are especially vulnerable, as their magnesium needs increase during this time.

How to Prevent Grass Tetany

Fortunately, you can take proactive steps to protect your herd before problems arise.

1. Supplement with Magnesium.
A high-magnesium mineral, such as Purina® Wind and Rain® Storm® Hi-Mag, is one of the most effective ways to safeguard your cattle. For best results:

• Begin offering mineral 2–3 weeks before cattle are turned out on lush spring grass.
• Maintain consistent intake for at least 60 days after spring growth begins.

2. Manage Pasture Grazing.

• Allow young, less susceptible cows to graze high-risk pastures first.
• Hold older, lactating cows off pasture until grasses are at least 4 to 6 inches tall.

Don’t Wait for Symptoms

By the time a cow shows signs of grass tetany, it may be too late to intervene. Prevention is the best defense—especially during spring’s rapid forage changes.

Start your herd on the path to a healthier season with Wind and Rain® Storm® Hi-Mag mineral. Contact your local FCS feed specialist to learn more.