They forage for grasses and even weeds and other plants that they instinctively know will meet their nutritional needs.
Depending on the stabling conditions not all horses have access to grass 24/7. In this case, hay nets or slow feeders are recommended so their digestive system can continue to work efficiently as was designed by nature.
As a general rule, healthy horses should be fed a diet that consists mainly of grass hays. Timothy hay is an excellent well rounded hay that meets most of their nutritional needs. If Timothy is not available in your area, there are other grasses that work just as well.
About 80% of the diet should be grass. Alfalfa can make up the other 20%. Although alfalfa is a legume hay and not a grass, it is the one exception that causes the least problems. A diet that is more alfalfa than grass can cause mineral imbalances.
Horses should never be fed grains such as wheat, barley, corn, oats, processed grain mixes like senior feed etc. This wrecks havoc on their digestive systems causing long term health issues.
Never feed your horse anything with sweeteners of any kind. See my post No Sweets
A typical health maintenance diet for horses without any health issues is as follows:
80% to 90% grass hay
10% to 20% alfalfa cubes or pellets (can be a mix of alfalfa timothy)
- Seaweed (for minerals) such as Source Micronutrients or
- Free Choice Salt
- ABC's Plus also by Advanced Biological Concepts. This is an excellent digestive aid that increases the absorption rate of the nutrients in the feed and supplements. It acts as a preventive to avoid future digestive disorders.
- Omega 3 Fatty Acids. These can be found in flax, chia and other oils such as coconut. A good form is HorseTech's NutraFlax . This supplements the needed fatty acids that the dried grasses lack and helps keep the joints healthy.
These are basic guidelines as long as your horse is not having any health issues and is used as a maintenance type diet.
Anytime your horse is given a paste wormer or medication, digestive flora are depleted which causes diarrhea, gas, colic, and a host of other mild to serious problems. After worming or administering medications, you will need to supplement with a probiotic to replenish the digestive flora. A good one is BioMos and Yeasacc . This can also be used during times of stress such as trailering, showing, training etc or if you see signs of digestive upset.
Depending on the needs of your horse, the supplements may need to be adjusted but the core diet should always remain as primarily grass hay.