As a mild autumn continues, extending the grazing season can be tempting. Even after the indoor feeding season has begun, weather permitting, horses in Finland can still spend September days on pasture rather than in their usual turnout paddocks.
Even if the pasture has been mostly grazed down, horses move around together looking for the last blades of grass, adding variety to their day. As grazing becomes scarcer, however, it is important to ensure that horses receive enough nutrients from supplementary feeding.
Night frosts change the situation, however. When temperatures fall below freezing, the composition of pasture grass changes. Horses should not be allowed to eat frozen grass in the same way as ordinary pasture grass. What actually happens to grass during a frosty night, and why does it matter for a horse's digestion?
Plants do not stop functioning all at once in autumn. As temperatures fall, their metabolism slows, while other changes take place as they prepare for winter.
Frost damages plant tissue. When grass freezes and later thaws, its structure changes. Frost does not make the sugars in grass disappear either. On the contrary, cold autumn conditions can affect how much water-soluble sugar accumulates in the plant.
The main concern for a horse's digestion is the metabolic burden of sugar-rich grass. Changes occur as gut microbes break down feed, but sugars absorbed in the small intestine and their effects on blood glucose and insulin levels are also important.
For this reason, autumn grazing deserves particular attention when night frosts become more frequent.
A single frosty night does not automatically mean that all horses must be taken off pasture immediately. Factors include the individual horse, the condition of the pasture, the severity of the frost and how much grass the horse eats.
What about the horse's digestion?
A horse's digestive system is adapted to processing small amounts of forage almost continuously. In autumn, the problem is therefore usually not just frozen grass, but changes in the amount and composition of pasture grass and sudden changes in feeding.
A horse's large intestine and caecum contain many microbes involved in fibre digestion. These microbes are adapted to the horse's usual diet, so dietary changes should be made gradually.
When the grazing season ends, the proportion of dry hay in the horse's diet usually increases. If this change happens quickly, the gut microbiota has to adapt to the new feed in a short time.
It is therefore worth planning the end of the grazing season and the transition to winter feeding in advance.
Do not wait until the pasture is grazed bare
In autumn, pasture no longer provides as many nutrients as it does in summer. At the same time, the horse's energy needs may change as the weather cools and activity levels vary.
A planned approach to autumn changes is especially important for horses with particular dietary sensitivities.
When a horse moves from pasture to its stable-season diet, good-quality forage remains the foundation of feeding. Other hay-based products can be included alongside dry hay when needed.
Biohansa hay pellets are made from dried hay and can be used, for example, to supplement a horse's forage intake. The pellets are easy to portion when you want to monitor precisely how much hay your horse receives.
When planning feeding, always take into account the horse's overall diet, individual needs and the nutritional value of the hay being used.
The most important thing for the horse is to avoid unnecessarily rapid changes. Move gradually from pasture grass towards winter feeding while monitoring the horse's weight, body condition and digestion.
The most important autumn feeding tip is simple: plan the transition before the pasture runs out.
