Grass Tetany is still a problem for Irish Farmers – Prevention with supplementing Magnesium

Grass Tetany is still a problem for Irish Farmers – Prevention with supplementing Magnesium

Farmers across Ireland are facing another unusual Spring season in the Diary Industry. Farmers are looking for new and innovative ways to make their farms more productive by producing healthier cows. Ensuring a Healthy Animal is worth the investment required. In this blog, we take another look at ‘Grass Tetany’ and how Terra NutriTECH is helping farmers all over the world to take preventive action.

What is Grass Tetany/Staggers and is it dangerous?

Hypomagnesemia is a technical term and is characterised by a subnormal level of magnesium in the blood. It is generally associated with grazing. Typical symptoms are reduced milk yield (up to 15% loss of production), nervousness and muscular tremors.

In the acute form, the cow staggers around, froths at the mouth, collapses and ultimately dies. If untreated, 60% / 80% of animals will die.

Although treating the affected animal is a priority, we also aim to give advice and resources to farmers that aim to avoid the problem from reoccurring year after year.

Very little milk fever and grass tetany.

Source: Independent IFAC Report

Research shows that cows are known to have low stores of magnesium in their bodies.  Getting an adequate amount of minerals is shown to have a positive effect on reducing Grass Tetany. While it’s evident that cows have magnesium in their bones, they can only mobilise this very slowly.

Cows are typically poor at absorbing magnesium in their guts. This means they require daily intakes of magnesium. Lactating animals during this season have an increased requirement for magnesium also. Anything that affects the gut function or DMI dry matter intake can disrupt magnesium absorption.

How to Prevent Grass Tetany? 

Supplementing Dairy Cows with Magnesium for better Animal Health

  • Magnesium can be given through water. This is the most effective way of ensuring adequate mineral intake specifically suited to the needs of your herd. It is cost-effective and reduces the intensity of labour requirements. 
  • Using TMR, magnesium can also be added directly to the feed.
  • Other options such as Palatable licks and high magnesium buckets are also used.
  • We can also feed fibre in the diet during the spring to reduce the risk from lush spring grass high in oils and low in fibre. Most care should be taken when lush low covers are being grazed in particular.
  • Pasture dusting magnesium can be done also but is very labour intensive and cannot be monitored.

One less job to do and I have healthier cows that hold condition after calving.

Source: Independent IFAC Report

There are a number of things that affect magnesium uptake for Dairy Cows

• Dry matter intake (can be affected by a number of things)
• Potassium(too high)
• Sodium (too little)
• Ammonia or nitrogen high
• Not enough fibre
• CLA fats in spring grass can affect magnesium uptake

We know cows need daily intakes and the spring season poses some increased risks. Farmers need to ensure magnesium supplementation during this high-risk period.

Learn more about our Mineral Range. Combining our signature mineral range with our accurate dispensing system ensures a precise amount of minerals for dairy and beef cattle. This leads to healthier cows and more profitable farms. A Precision Nutrition Plan gives them the vigour to develop, grow and reproduce, and strong immunity to fight off infections. We offer a range of custom mineral blends that target better animal health. Grass Tetany, Milk Fever and other common cattle conditions can be significantly reduced using better mineral management.


Call Ronan: (087) 708 6714

Email: [email protected]