Hypomagnesaemia is a potentially life-threatening condition that affects cattle and sheep, especially during periods of rapid grass growth. Being aware of the causes, symptoms, and preventive measures is key to protecting your herd.
What is Hypomagnesaemia?
Hypomagnesaemia occurs when livestock do not receive enough magnesium (Mg) in their diet. Magnesium plays a crucial role in nerve and muscle function, and a deficiency can lead to muscle tremors, staggering, and even sudden death. Unfortunately, magnesium reserves in livestock are limited, and they rely on their daily intake from grazing. When the magnesium content in pasture is low, animals are at risk.
Why is Autumn a High-Risk Time?
During autumn, pastures tend to be high in potassium and nitrogen due to fertiliser use and rapid grass growth, but these conditions often result in lower magnesium availability in the grass. Moreover, cool, wet weather can further reduce the absorption of magnesium from forage. Cows and sheep that are grazing on these magnesium-deficient pastures are at an elevated risk of developing Grass Staggers.
Risk Factors for Hypomagnesaemia
- Lush Grass Growth: Rapidly growing pasture is often high in water and low in magnesium, making it less nutritionally balanced for livestock.
- High Potassium and Nitrogen Levels: Fertilised pastures can be high in potassium and nitrogen, which can interfere with the animal’s ability to absorb magnesium from the grass.
- Stress and Poor Weather: Cold, wet conditions and stress caused by moving animals or bad weather can increase the demand for magnesium.
- High-Producing Animals: Lactating cows and ewes have a higher demand for magnesium, making them more vulnerable to Grass Staggers.
Symptoms of Hypomagnesaemia
Early detection of Grass Staggers is critical because the condition can progress rapidly. Key signs to look out for include:
- Restlessness and Nervousness
- Muscle Tremors or Twitching
- Uncoordinated Movement or Staggering
- Collapsing and Convulsions
- Sudden Death (in severe cases)
If you observe any of these signs, immediate action is needed to prevent fatalities.
Preventing Hypomagnesaemia
- Magnesium Supplementation:
- One of the most effective ways to prevent Grass Staggers is by providing magnesium supplements. These can be delivered through:
- Magnesium-rich licks or blocks: Placing these in fields ensures that livestock have easy access to extra magnesium.
- Feed supplementation: Adding magnesium to concentrates or silage can also boost intake.
- One of the most effective ways to prevent Grass Staggers is by providing magnesium supplements. These can be delivered through:
- Limit Grazing on High-Risk Pastures:
- Restrict access to fields with high nitrogen or potassium content, particularly after heavy rainfall or during cold spells when the risk is highest. Where possible, rotate grazing areas to avoid over-dependence on high-risk pastures.
- Monitor High-Risk Groups:
- Pay special attention to lactating cows and ewes, as well as older animals, as they are more susceptible to magnesium deficiency. Keep them in areas with supplemented feeds or pasture that has been properly managed.
- Manage Stress:
- Stressful events such as moving animals, sudden weather changes, or mixing groups can increase the likelihood of hypomagnesaemia. Minimise unnecessary stressors during high-risk periods.
How Murray Farmcare Can Help
At Murray Farmcare, we understand the serious impact hypomagnesaemia can have on your herd or flock, especially during the autumn months when conditions are most favorable for the disease. Our Territory Managers are ready to support you with tailored solutions to protect your livestock. Here’s how we can help:
- Recommend Magnesium Supplements: We stock a variety of magnesium supplements that can be tailored to your herd’s needs.
- Practical Advice: Whether it’s rotating grazing areas or optimising feed supplementation, our Territory Managers are here to provide hands-on, practical guidance.
Don’t Wait for a Crisis
Hypomagnesaemia can develop quickly and lead to sudden losses. Taking proactive steps this autumn will help protect your herd and avoid the devastating impacts of Grass Staggers.
For more information or to arrange a consultation with your Murray Farmcare Territory Manager, contact us today. We’re here to help you ensure your animals stay healthy and productive throughout the autumn grazing period.