Are Your Cows at Risk of Grass Staggers?

As Spring very slowly approaches, and the wet weather hopefully dries up soon, we will see cows going out on grass again.  One thing we want to avoid at this time is exposing them to the risk of grass staggers.

Grass staggers, also called grass tetany (or hypomagnesaemia if you want to get technical) is a metabolic disorder that can lead to sudden death in cows.  It happens when cows have insufficient magnesium supply from their diet, which can happen on fresh spring grass.  Freshly calved dairy cows, older cows, and cows under stress are most at risk, but it can affect any cow.

So, how do you prevent grass staggers?

Do not apply excessive potash to your fields in Spring, as potash may lock up magnesium and make it unavailable to grazing animals.  You must also ensure your cows are receiving sufficient magnesium, by testing the quality of feed they are getting.  In dairy cows, magnesium supplements are highly recommended in the weeks before calving and up to a month after calving.  There are many options for feeding magnesium supplements, such as minerals to mix into the feed, boluses, or minerals to put into the water.

Feeding roughage when the cows first go out to grass can also help reduce the risk of grass tetany.  One of the reasons grass tetany occurs on lush grass is that it is low on fibre and does not remain in the rumen long enough for the cow to absorb all the nutrients.

For more information speak with your nutritionist, soils adviser, or  Prevention will be better than cure!  The longer-term answer will be in the soil and not in the animal diet!