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What Is Grass Tetany in Cattle? (Symptoms, Prevention & Grazing Advice)
What is Grass Tetany?
Grass tetany (also called staggers) is a metabolic disorder in cattle caused by low magnesium levels, most often seen in spring when cows graze rapidly growing grass. It’s an emergency and needs fast action.
What Are the Symptoms of Grass Tetany?
- Muscle twitching or tremors
- Staggering or unsteady gait
- Excitability or restlessness
- Loss of appetite
- In severe cases, collapse, convulsions, and death
Why Does Grass Tetany Happen?
- Grazing young, lush grass (especially after fertiliser use)
- Low magnesium and high potassium in pasture
- Older cows and heavy milkers are at higher risk
- Cold, wet weather can increase risk
How Can You Prevent Grass Tetany?
- Provide magnesium supplements, especially in spring—see our cattle feed and supplements
- Avoid sudden turnout onto lush, fertilised pasture
- Rotate grazing and include older grasses or mixed species
- Monitor high-risk cows closely
- Ensure cows have access to clean water and aren’t stressed
What Should You Do If You Suspect Grass Tetany?
- Act immediately—grass tetany can be fatal within hours
- Call your vet for magnesium treatment
- Move the cow to a quiet area with clean animal bedding
- Prevent further stress and disturbance
FAQs
Is grass tetany only a spring problem?
It’s most common in spring, but can occur whenever cows graze young, lush grass.
It’s most common in spring, but can occur whenever cows graze young, lush grass.
Can you prevent grass tetany with diet?
Yes—magnesium supplementation and careful grazing management are key.
Yes—magnesium supplementation and careful grazing management are key.
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