There are a few well-defined, unchangeable rules, when it comes to feeding your horse. You can do a lot of different things, however, you have to follow the hard and fast rules, or your horse will suffer for it. There aren’t very many that are absolutely critical: just these seven.
1. The majority of your horse’s diet must be made up of forage. Most of your horse’s diet has to consist of pasture, hay, or hay products (like hay pellets or hay cubes). You can’t do anything about it, so just go with it.
2. Your horse should always have unlimited access to fresh, clean water.
3. You should always feed a good-quality feed. I mean really; think about it. Poor quality feed (e.g., brown, moldy hay) lack just about everything that feed is supposed to provide your horse. Things like mold, dust, and fungus aren’t good for your horse; a lack of green color in hay, for example, means that a lot of the nutritional value is gone. If you don’t care enough about your horse to feed the best feed that’s available, either sell him, or find him a good home.
4. If your horse needs extra energy, give it to him. If a horse is exercising a lot, he will need a lot of calories. That doesn’t necessarily mean more hay; horses can fill up on hay and not be able to get enough of it in their stomach’s to satisfy their caloric needs. Horse with extra caloric needs need extra calories, especially in the form of grains and/or fats.
5. If you feed your horse grain, never give him more than 5 pounds at one feeding. Too much grain has the potential to cause your horse metabolic problems, as well as laminitis.
6. Feed regularly, and at least twice a day. There’s no apparent advantage to feeding more than three times a day, however.
7. If you make dietary changes for your horse, do them, slowly, over a period of a couple of weeks (for a variety of reasons, including colic prevention).
Once you understand what you can feed your horse, and what your horse must have in his diet, actually feeding your horse becomes mostly a matter of knowing what you want. If you have well-defined goals as to what you want from your horse (from a nutritional point-of-view), you can fairly easily choose feed items that might help you reach them!