It’s integral to the survival of the farm to watch out for telling signs your cattle might be suffering.

Grass Staggers, or hypomagnesaemia, is magnesium deficiency in livestock and can lead to critical conditions if not caught early. Farmers use a high magnesium diet and supplements in different forms to ensure their cattle consume enough of the element to prevent deficiency, as a deficiency of it can prove to be fatal.

Diseases such as grass staggers can greatly affect your cattle’s health, milk production, and profit margins, so it’s essential to be aware of these diseases, the causes, symptoms, and how to go about preventing and treating it.

What is Grass Staggers?

Grass Staggers is a critical condition that occurs in cattle and other livestock when animals experience magnesium deficiency. It is also known as grass tetany, wheat pasture poisoning, magnesium tetany, and hypomagnesaemia. Although this condition can be extremely hard to detect in cattle, most farmers have prevention methods in place and knowledge of what to look out for to detect it before it becomes critical.

What Causes Grass Staggers in Cattle?

Cattle are unable to control levels of magnesium in the blood and rely on magnesium in their diet to supplement the much-needed element. It can occur during Autumn, winter, and spring months when the grass pastures that cattle graze on grow rapidly and do not retain sufficient levels of magnesium.

Magnesium levels can also be diminished through the use of fertiliser, partly because of the relative increased growth rate, but also because the potassium in the fertiliser directly inhibits uptake of magnesium by the grass. Furthermore, it can occur due to increased metabolic demands of the substance during lactation and pregnancy, so grass grazing lactating cows are the most at risk of the disease.

Check out this white paper for optimal supplementation and dosing strategies for cows of any size with different feeds.

What are the symptoms of Grass Staggers?

In some cases, grass staggers can be extremely difficult to detect, so it’s essential to be able to spot any minor symptoms that you should be on the lookout for in your herd. Unfortunately, most cases of grass staggers are only detected once the cow has been found deceased. A common finding in these cases are marks on the grass where the cows’ legs were outstretched and thrashing before they succumbed to the disease. This is called “tetany” when the muscles contract uncontrollably.

If you’re astute enough to spot any symptoms before it becomes critical, this is what to look out for:

  • Change in character
  • Nervousness
  • Difficulty handling
  • Over alertness
  • Restlessness
  • Muscle twitching
  • Later stages of the disease may trigger staggering (hence the name)
  • Even aggression

To find out more about the symptoms to watch out for to prevent this disease, check out the Tasmanian Government website.

Can Calves get Grass Staggers?

Older cows, especially if they are feeding calves or suffer from other health issues, are more susceptible to low magnesium levels, though it also occasionally affects younger cattle and calves.

What does Grass Tetany Look Like?

Cattle hold magnesium in their bones and muscles but can not readily access these stores as and when it’s needed for their blood. They lose a lot of magnesium through their excrement, and therefore require supplementation of this element through their feed to meet their daily requirements. Magnesium deficiency can be detected in blood and urine tests, so consult with your vet about monitoring these levels.

Keep an eye on your dairy cows, particularly during lactation and pregnancy, as they are at the highest risk of magnesium deficiency. Cattle at peak lactation (6-8 weeks post-calving) need a constant supply of magnesium in their feed due to the huge amount lost through milk production.

If your cattle or sheep are predominantly grass grazing animals and receive little or no hay supplements, they may be at a higher risk of grass tetany. In addition to this, if they have recently moved paddocks or are outside, grazing in wet and windy weather with little shelter, they may be fasting for periods and not be receiving the sufficient nutrients they need. Animals with other health issues or are underweight or overweight can also be at risk.

How do you Treat Grass Staggers?

For treatment, please check with your veterinarian for the best course of action as it may be on a case to case basis. Ideally, maintaining adequate magnesium levels in the blood through diet and supplements are the best preventative methods, but supplementation also needs to be optimised due to a risk of excess magnesium. Supplements can be in the form of pellets, lick blocks, powder, capsules, or soluble forms of magnesium to add to their feed. Each method has its own advantages and limitations, so each farm should research and find the best magnesium supplement for their cattle, conditions, and feeding strategies.

In severe cases, intravenous injections can be administered by a veterinarian, though close monitoring is necessary. For more treatment, prevention, and control check out this paper for New Zealand Society of Animal Production.

How to Prevent Grass Staggers in Cattle

Investing in indoor farming practices enables farmers and their teams to monitor health issues and feed intake and encourage a well balanced diet for individual cows. By controlling the feed per cow with a reliable, quality supply of feed, you can help maintain each and every dairy cow’s optimum size, health, and milk yield. Should they arise, any changes in their eating habits can be easily identified, allowing you to quickly address them and minimize food wastage.