The risks of spring grass

Now that spring has arrived, many horses get to enjoy turnout and pasture time. But beware, there are also some risks that come along with spring grass. If you look at fresh grass, it consists of 80 to 85% water and 15 to 20% dry matter. Dry matter is what is left when you take out all the water. It contains fiber, proteins, sugars, vitamins and minerals. Especially the sugar content (and specifically fructan) in grass can vary a lot. This is due to various factors such as the age of the grass, the temperature, the time of day and the pasture management. But what exactly happens in the spring? 


The grass grows fastest in the spring. During the day, under the influence of the sun, it produces a lot of sugars. The more the sun shines, the more sugars are produced. At night, these sugars are converted into fiber, which causes the grass to grow. However, cold nights still occur regularly in the spring. When the temperature falls below 8-10 degrees Celsius, the conversion from sugar to fiber stops. As a result, the sugar is still in the grass the next morning. The production of sugar does not stop, so the sugar accumulates in the blades of the grass. 


This high sugar content is actually not a problem for wild horses. They can use this well to recuperate after the often poor winter. But it could cause problems for our domestic horses. Often the pastures where we keep our horses consist of grasses that already have a natural high sugar content in themselves (such as perennial ryegrass). If extra sugar is added, this causes very high peaks. In addition, most horses receive good quality roughage in the winter. In contrast to wild horses, they do not lack any nutrients over winter and therefore do not need extra nutrients to recover strength. 


A large majority horses will not be directly affected by the high sugar content, although it is not good for the intestinal flora to always have to process these high sugar concentrations. Horses that are sensitive to it can become laminitic. Another consequence is that it can make the horse overweight or obese. If the horse takes in more energy (sugars) than it uses, its weight will increase. And weight issues can lead to all kinds of other health problems. In addition to the high sugar content, the sudden change in diet can also cause problems. If the horse eats hay all winter, its intestinal flora is adjusted to this. Sudden changes in the diet, such as suddenly grazing on a pasture all day, can cause disturbances which can lead to diarrhoea or colic. 



What can you do to allow your horse enjoy the spring grass as safely as possible? 

  • Build up grazing time slowly 

Do not immediately turn your horse on the field all day, but start with an hour. In the beginning, preferably let them graze in the morning, when the sugar content is lowest. Please note: if there has been a cold night followed by a sunny day, the sugar levels can still be high in the morning. 

  • Keep a close eye on your horse’s body condition 

Obesity can cause various health issues. If you notice that your horse is gaining weight, see what adjustments you can make to the diet and/or training. 

  • Ensure good pasture management 

To have a healthy pasture it is important that it is fertilized regularly (adapted to horses). Grass that grows on poorly fertilized soil contains a relatively large amount of sugar. 

  • Turn horses that are prone to laminitis out to grazing as little as possible 

Preferably choose a paddock in which you offer roughage. A roughage analysis can be useful to see how many sugars there are in your roughage. 

  • Choose a special grass mixture for horses 

There are special grass seed mixes on the market that have a lower sugar content. 

  • Is the horse stabled at night? Then make sure it eats a generous portion of hay in the morning at breakfast before going out to pasture. For example, when it already has roughage in it stomach, the horse will ‘attack’ the tasty green grass less. 

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