Grains contain a lot of starch which can be converted by horses into energy. However, the digestibility of starch varies between different types of cereals. Some grains must be processed first before horses can digest them effectively. Horses enjoy eating cereals as they are quite nutritious but they lack variety. Therefore, a ration consisting solely of cereals or grains isn’t healthy for horses. Nonetheless, the most commonly used grains in horse feed are oats, corn, barley and wheat. More about these cereals can be found below.

Oats

Oats are the grains that have traditionally been used to feed working horses. They contain more crude fiber than other cereals which encourages more chewing and aids digestion. In addition, oats have a higher fat content than other cereals which positively impacts a horse’s coat shine. 

Nonetheless, oat has a calcium-phosphorus ratio of ± 1:3, meaning oats contain more phosphorus than calcium. However, the ideal calcium-phosphorus ratio of the diet is 2:1. Thus, combining oats with feeds that contain more calcium than phosphorus (such as Hartog Lucerne Mix), can help to balance the diet.

Finally, there is often a question about whether oats make horses “hot”. No specific answer has been found yet as to why this might happen. Although, it might be related to the fact that oats are more easily digested, with starch breaking down faster than in other grains. This causes the resulting sugar to quickly enter the bloodstream, leading to a rapid energy boost.

Concerning Hartog products, Hartog Energy is the concentrated feed based on oats. As the energy from the oats is released quickly, it is particularly suitable for disciplines that require more fast-release energy such as racing, eventing and show-jumping.

Cut Oats

Cut oats, containing only the oat plant without the grain, are also frequently used for horse feed. As grain is not used, they’re lower in energy. Plus, due to the oat plant’s fiber content, cut oats are better digested by horses. In the Hartog range, cut oats have been added to products like Hartog Lucerne Mix and Hartog Grass Mix.

Corn

Corn, also known as maize, was originally a subtropical crop. However, now it is also cultivated in cooler climates like the Netherlands. Corn can be fed in various forms such as silage, crushed corn, cracked corn, corn pellets or cornmeal.

The starch in corn is different than in other cereals and is less digestible for horses. It can lead to an overgrowth of “wrong” bacteria, even resulting in colic or diarrhoea. Thus, whole corn kernels are less suitable for horses as they are harder to digest.

Heat treatment or special processing can make corn starch more digestible. Maize used in Hartog products undergoes heat treatment, making it more suitable for horses. However, corn is very energy-dense, low in protein, and very poor in minerals, so it should be combined with roughage. Hartog Lucerne Mix, for example, can supplement fiber, protein and essential amino acids alongside corn pellets. 

Due to its high energy content and low nutrient profile, corn is known as a “fattening” feed. When more starch (such as from corn) is fed, horses’ digestion adapts by producing more starch-digesting enzymes. Therefore, a horse needs to be introduced to corn slowly. If a horse is used to it, an average 500 kg horse can consume 1-2 kg of corn pellets per day.

Corn Silage

Corn silage, which includes stalk, leaves, and cob, is chopped and ensiled, making it structurally similar to roughage. To be fed, horses sometimes need time to adapt to corn silage’s sour smell and taste. But be cautious, as any mould or spoilage in corn silage can cause colic.

Barley

To horses, barley can be fed in different forms, including ground, crushed or whole. In general, barley is high in starch and low in crude fiber. Thus, it provides more energy per kilogram in comparison to oats. However, barley’s starch structure differs from oats, making it slower to digest. To improve its digestibility, barley is often crushed or flaked, and whole barley should be soaked in warm water before being fed to horses.

When feeding barley alone, limit the amount to 400–800 grams per serving. Barley also has an unbalanced calcium-phosphorus ratio, so if used heavily, it’s beneficial to add calcium sources like Hartog Lucerne Mix.

The raw barley’s fiber content supports a horse’s digestive system, promoting gradual movement through the gut. Like oats, barley can have a stimulating effect, though it releases energy more slowly, making it suitable for endurance sports, dressage, or driving. From the Hartog line, Hartog Energy is based on barley.

Wheat

Most wheat in horse feed is used as by-products, such as bran and middlings. Feeding pure wheat to horses is discouraged due to its high starch content, which makes it nutritionally unilateral. In terms of wheat’s energy content, it can be placed between oats and barley.

Wheat bran, which consists of the grain’s outer husks, is better served moist due to its lightweight particles. When wetted, it positively stimulates intestinal movements.

A downside of pure wheat for horses is that it can form clumps when wet, potentially causing blockages in the stomach or intestines.

In concentrated feeds, wheat is used up to 20% (200 grams per kg of feed). Like other grains, wheat is low in calcium, with a calcium-phosphorus ratio of around 1:5. However, if wheat is used in limited amounts, it’s unlikely to disrupt the balance, unless combined with large amounts of other grains.