The cereals most commonly used in horse feeding are oats and, often included in ready-made feeds, barley and maize. As we have already mentioned, the main purpose of feeding cereals is to supply energy. It comes above all from the starch inside the kernel, but in some cereals it is “packed” in such a way that access to it is very difficult. That is why selected cereals have to be hydrothermally processed before feeding. This causes structural changes in the feed particles, improving enzyme access and, as a result, increasing the digestibility of nutrients such as starch.
The only cereal that does not need hydrothermal processing before it is fed to horses is oats. The starch it contains is loosely packed, so digestive enzymes in the small intestine have much easier access to it, and the energy becomes available to the horse more quickly. This means that oats are rich in easily digested starch and can cause excitability. The protein content of this cereal averages 12% and is not much higher than in barley or maize. One of the main advantages of oats is their high fibre content (11-30%), which counters an increase in their volume in the stomach. Healthy adult horses are best fed the whole grain. For horses with weaker teeth, or older horses, if you choose rolled or crushed oats, they should be fed within 2-3 days so that they do not lose nutritional value.
Barley and maize are cereals whose energy is hard for the horse to access, so it is worth choosing them in micronised form. Micronising not only increases digestibility and the availability of nutrients; it also prevents the growth of fungi and mould, destroys existing bacteria, viruses and yeasts, and has a positive effect on palatability. Is rolling or crushing not enough? Unfortunately not. Studies of digestibility in horses show that rolling the grain increases starch digestibility by only 1%. Even though these cereals need processing, they are a very valuable feed. Barley has a higher nutritional value than oats. It is more energy-dense and does not cause excitability. Because it is lower in fibre, however, it needs more careful rationing to avoid health problems. Maize grain, meanwhile, is valued for its particularly high energy value and works very well in the diet of horses in intense work that need a lot of energy. Its drawback is a very low content of protein and fibre.
And what about wheat? Because of its high gluten content it risks making the digesta stick together, so its share of the ration should be small. Like barley and maize it needs processing beforehand, but in its case extrusion is used, which also makes it less sticky. Finally, rye is worth a mention: feeding it is not recommended because of a high risk of colic. It also has a bitter taste, and horses are not very keen to eat it.
Worth knowing… All cereals have an excessive phosphorus-to-calcium ratio and are low in vitamins and minerals, so a diet based on hay and cereal should be completed with the necessary supplements. The same applies to combining ready-made feeds with oats!