Acclimating horses to grass in spring correctly

In spring, both horses and their owners can hardly wait: They gallop out to the pasture! Finally enjoying fresh air and sunshine and nibbling on lush greenery. But the supposed pasture paradise can be deceptive. If the horse is turned out on a paddock with fresh spring grass without any preparation, this can have far-reaching health consequences for the horse. Careful acclimatisation is therefore an absolute must for every horse, every horse owner and stable manager!

Why acclimate horses to grass at all?

Horses have a very delicate and sensitive digestive system that thrives on microorganisms in the gut that break down plant matter such as cellulose. These bacteria are essential for the horse’s intestinal health. Over the winter, the intestinal bacteria feed exclusively on roughage, e.g. in the form of hay. An abrupt change to pure grass feeding in spring would lead to an overload and, as a result, a mass death of the microbes. This is due to the sugars contained in grass, such as fructan, which are necessary for grass growth and are therefore present in large quantities. Generally, intestinal bacteria can metabolise the sugars in grass well. However, without a careful approach in spring, they are caught off guard, so to speak, and cannot adapt to the new feeding situation and die off as a result. The endotoxins (toxins) released by the microbial death enter the horse’s bloodstream, constrict the blood capillaries and make blood circulation more difficult.

Typical signs of a wrong or insufficient feed change of a horse are diarrhoea and free faecal water syndrome, colic, muscle diseases (myopathies) and in the worst case laminitis (pododermatitis). These problems can be prevented by gently accustoming the horse to fresh pasture grass and by regular exercise.

What is fructan anyway?

The highest fructan contents are found both at the beginning of the grazing season in May and towards the end of the paddock season in October, November. Temperature also has a significant influence on fructan content. Scientific research has shown that the fructan level is related to the average nightly temperature of the past 48 hours. If the thermometer drops below 8°C at night, sugar is stored more in the plant and the fructan content is thus higher. If the temperature rises higher than 8°C for at least two days, the plant starts to grow, the fructan stores are emptied and the risk to horse health decreases.

Fluctuating fructan content in the course of the year

Another problem arises in the course of the grazing season: the forage supply decreases, almost all grass has been eaten, the weather is very dry and the temperatures drop again. In autumn, conditions are similar to those in spring. The grass cannot grow in dry or cold weather, which is why it fills its energy stores. This increases the fructan content. It is therefore better to end the grazing season early and add hay so that the intestinal flora can adjust to the winter feed in time.

All important scenarios with the corresponding fructan contents are summarised here once again:

Soil temperature < 8°

• Sunny & frosty: fructan content very high
• Frosty & cloudy: fructan content medium to high
• Rainy/cloudy: fructan content medium

Soil temperature > 8 °C

• Sunny: fructan content low in the morning, medium in the afternoon
• Rainy: fructan content low
• Long dry spells: high fructan content

When does the grazing season for horses begin?

When grazing is possible depends entirely on the area and the soil. In some areas year-round grazing is possible. In other areas, e.g. lower lying areas with clay soil, the fields cannot be used in winter. If horses have been kept indoors or in grassless paddocks all winter, the transition to grass-feeding must be made slowly. When the grazing season can begin must be assessed individually and depending on the horse breed, weather, soil, outside temperature and grass growth.

Ponies and cobs can be more susceptible to feed-related metabolic diseases, which is why they should be treated with particular care and at a later stage than warmbloods and throughbreds.

The optimal grass length for starting with grazing is about 20 cm.

This is what you should consider when introducing your horse to grass:

• Feed hay before turnout, no concentrated feed.
• Increase grazing time slowly and gradually (with a schedule).
• If your horse suffers from diarrhoea, do not extend the grazing time further, but increase the amount of hay until the intestinal flora has normalised. Then you can resume the increase.
• Reduce the amount of concentrated feed during the acclimating period.
• After grazing, give hay and straw first, then concentrate.
• Give your horse sufficient exercise. The extra calories from the pasture grass should be burnt through exercise. Exercise will also keep the digestion going.
• Wormers should be given 14 days before and not during the acclimating period. The medication can only put additional stress on the detoxification and digestive metabolism.

For horses with metabolic problems, grazing should be done even more carefully than for horses without health problems. Horses with EMS, PPID, laminitis or PSSM should not be allowed to graze until grass has grown to a minimum of 25 cm, but not when the night is frosty and the next morning is sunny. Rather, let them out to pasture when temperatures are higher in the afternoon and the sky is cloudy. In some cases it may be advisable to refrain from grazing altogether.

Proper acclimatisation of the horse to grass – with a plan

Keep in mind that the intestinal flora needs at least 2 to 4 weeks to adjust to a change of feed and thus to a changed ingredient composition. Therefore, only gradually increase the grazing time by max. 15 minutes, better 5-10 minutes. Start turning out only in the afternoon for the first two weeks, when the fructan stores are sufficiently empty. Afterwards, divide the grazing times between morning and afternoon.

How can I support my horse during the acclimatisation?

The best protection against diarrhoea and free faecal water, laminitis and colic is a healthy, well-functioning intestinal flora and an intact digestive tract. The horse’s intestinal health is severely stressed by the change in feed from winter to summer feed and vice versa. With the right vitamin and mineral supplement and herbs you can support your horse and its intestinal bacteria during this phase.

Sugar-containing grasses are usually low in nutrients, which is why a sufficient supply of trace elements and minerals is particularly important. For horses with metabolic problems, the vitamin and mineral supplement Original Landmühle Vitamin and Mineral Supplement Metabolism Premium is a useful supplement.

Horses without previous illnesses or which are not hypersensitive to feed changes, carbohydrates and proteins can receive their mineral supply via the Original Landmühle Vitamin and Mineral Supplement Premium. Apart from the feed change in spring and autumn, a balanced supply of minerals and trace elements is necessary for the horse throughout the year, which you can support with this supplement.

Supporting the intestinal bacteria in a targeted way and thus improving tolerance can be achieved by adding probiotic feed additives. A prime example is live yeast, which stabilises the intestinal flora and thus increases the digestibility of the feed. For this purpose we can recommend the Original Landmühle Brewer’s Yeast. The Original Landmühle Prebiotic Balance Mash also has a prebiotic as well as a probiotic effect and maintains a healthy intestinal flora during acclimating to grass.

Many meadows, including horse pastures and paddocks, are poor in herbs. However, herbs can help to support the liver in detoxification, which can be particularly useful during the period of acclimatisation to grass. Therefore, it is important for horse health that natural components find their way into the horse’s bucket. You can achieve this, for example, with Original Landmühle Metabolism Herbs and Original Landmühle Liver Herbs.