fruktan

How fructan impacts horses

Basics That Every Horse Person Should Know

Often, the pastures which our horses graze on today, can no longer be compared to those from 200 years ago. Today’s high-performance dairy cow farming has resulted in the cultivation of grasses rich in energy, protein and sugar. Wild horses were used to grazing on large stretches of land with wild grasses, weeds and shrubs. Therefore, the grass supply is usually too lush for our domestic horses. These sown grass varieties usually contain a lot of fructan, which can be problematic for horses.

All About Fructan

What is Fructan?

Fructan is a long-chain carbohydrate that serves as energy storage for the excess energy of a plant. It is produced during photosynthesis. This happens, for example, when it is sunny but temperatures are low and the energy gained is not used immediately for growth but gets stored instead.

Why is Fructan in Grass Problematic?

Fructans are mainly metabolised by bacteria in the large intestine and are rapidly fermentable. A large intake can lead to a shift in the intestinal flora. The proportion of carbohydrate-splitting bacteria increases to the detriment of the raw fibre-splitting bacteria. When these die off, they release endotoxins, which enter the bloodstream via the damaged intestinal wall.

In the hoof corium, the toxins lead to small blood clots and thus worsen the blood circulation. These reactions of the body can contribute to the development of painful laminitis. For a long time it was thought that protein was the trigger for feed-induced laminitis, but this assumption is now outdated. Of course, the development of laminitis is related to other factors such as pre-existing diseases, poor hoof condition or a feed generally too rich in carbohydrates. In addition, it is discussed to what extent mould toxins (endophytes) living in symbiosis with grasses have an influence.

When is the Fructan Content in Grass High?

If the grass cannot grow, it stores more fructan, this happens when it is too cold or too dry. In Spring, at the beginning of the grazing season, and in Autumn, at the end of the grazing season, the highest levels of fructan are measured, as the grass is not able to grow well at this time. In August and September, on the other hand, the content is usually at its lowest. In her dissertation in 2002, Sandra Dahlhoff found that the fructan content is strongly dependent on the average temperature of the past 48 hours. When the temperatures increases, the fructan content decreases. In addition, the fructan content in the grass is mainly related to the average temperature at night. If it was colder than 8°C, the risk was generally higher. If the previous night was warmer, the risk got lower, unless it was dry for a long time. In short, whenever the grass grows, the fructan content decreases.

The Impact of Sun and Frost on Fructan Content

The following situation is particularly problematic: a lot of sun and frost. Photosynthesis can take place, but the energy produced is not converted into growth.

Contrary to popular belief among horse owners, short, mown grass is particularly high in fructan because it is stressed, can hardly grow and therefore accumulates fructan. However, regularly mowed grass that’s left at a hight around 15cm can help to reduce the sugar content in the grass.

Fertilising against fructan

The use of nitrogenous fertiliser in spring also helps against high fructan concentrations, since the sugar-rich high-performance grasses used today react to it. If the nutrients are lacking, the plant is stressed and produces fructan.

Fructan Content in Roughage

It is also important to remember that roughage also contains fructan. Up to 80% of the fructan from grass can end up in the hay. Special care should be taken with the first cut and the short second cut. Soaking the hay in warm water for at least 30 minutes rinses the sugar out of the hay. But be careful: at the same time bacteria can multiply explosively.

Which Grasses are Particularly Rich in Fructan?

Perennial ryegrass and Festuca pratensis are considered to be particularly rich in fructan. Fructan is mostly stored in the stem. In contrast, timothy, red fescue, meadow foxtail and ranunculus are low in fructan. Typically, field’s have a mixture of the different grass types.

What Affects the Fructan Content?

In order to determine whether the fructan risk is high, the composition of the grasses must be taken into account in addition to knowledge about fertilisation, vegetation stage, intensity of use and weather.

Grassland consists of three different supercategories of vegetation: grasses with a share of 70-80%, clovers with 10-15% and herbs also with 10-15%.

and how do I know when the risk is high?

There are different factors that can play a role when looking at fructan risk. Some things will decrease it and others will heighten it. Here are the most important factors to look out for.

Fertilisation and Fructan Levels

A plant can only grow well if it has all the nutrients it needs. Nitrogen fertilisation can therefore keep the fructan content lower, as can intensive use. Fertilisation with potassium, on the other hand, should be kept to a minimum because it can increase the fructan content.

Grass Species and Fructan Levels

Grass species such as perennial ryegrass and festuca pratensis are considerably higher in their fructan content. Timothy grass and cocksfoot, store significantly less fructan. It should be noted that there are also differences in the respective sub-types of the plant species. For example, there are also ryegrass varieties that are low in fructans.

If a new meadow is sown, a mixture of grass types should be used.

Grass Height and Fructan Levels

You should start spring turn-out when the grass is at least 6 inches in height (15cm). Since, no matter how high the grass is, the first 8 cm contain the highest sugar content. Frequent grazing also causes massive stress to the grass and leads to higher fructan content.

The Seasons Impact on Fructan Levels

Seasonal changes in the fructan content depend on factors such as temperature, intensity of light, growth period and plant species.

In May, the fructan content can be higher due to the fact that there is enough water, nutrients and a relatively high amount of sunlight already, but because of the occasional very low nightly temperatures, there is an energy surplus that cannot be used for growth yet. This energy is then stored in the plant as fructan. Over the summer, there are still differences in the concentrations, but the overall risk is significantly lower. In dry areas, the plants store higher amounts of fructan, since they do not receive enough water to start growing. At the end of summer and in autumn the fructan content often increases again, due to a combination of decreasing temperatures and plenty of sunshine.

Fructan x Happie Horses App

You want to know the actual risk of grazing according to the fructan level?  The premium version of the Happie Horse App recognises the risk for your horse based on your location and actual weather data.

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graphic showing the fructan risk

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