Horses under the care of humans eat a variety of diets depending on what work they do, age and health. Most horses are fed largely hay, with portions of oats given once a day. Others receive less hay and oats, but spend the day grazing grass in pastures. The mix of feed depends on how active the horse is; more work will require more calories from grains. Owners may also give their stock supplements to help keep the horses in prime condition. For example, beet pulp is the leftover remains of sugar beets that have been processed into table sugar. Beet pulp is high in fiber but still has roughly the same calories as oats. This makes it good for horses' digestion, while still being nutritionally valuable. Other supplements are highly-specialized blends that can help horses' joints, digestion issues and promote a lustrous coat. Every horse has a unique diet that works best for it, so most owners find that experimentation is the only way to find the best routine.
No matter what it is eating, every horse needs two other things to stay healthy: salt and water. Salt is provided in large, compressed chunks called salt blocks. Horses instinctively know when their body is low on salt and will chew on the block as needed. Water must be available at all times, as horses need over 10 gallons a day to stay hydrated. If you go for a long ride and won't be near a river, be sure to bring some water along for your horse.
There are only a few truly wild horses left, known as Przewalski's horses, which live in Mongolia. Most horses in the wild now are actually feral, descended from escaped domestic horses. They travel in family herds, grazing on grasses and shrubs and covering large territories over several weeks. Foals drink their mother's milk until they are old enough to eat grass. Livestock farmers complain that mustangs trample and steal grass from their sheep and cattle, so mustangs are increasingly being driven into captivity or more inhospitable lands. However, there are still places all around the world, including the United States, where feral horses roam free.
If you are wondering what you can feed a horse as a treat, the good news is that they enjoy a wide variety of snacks. Apples and carrots are the two most famous horse treats, but they also love sugar cubes, other vegetables and whole wheat bread. Most stables also have commercial horse treats around, which you can ask to give instead. Remember that you should always ask before feeding a horse, as it may be unfriendly or allergic to your offering. To give a horse a treat safely, hold out your hand with the treat in the center of your palm. Keep your fingers flat so that you don't accidentally get bitten. Let the horse come up to you and gently take the treat from your hand. While the horse is chewing, you might be able to reach up and stroke its neck. Horses have delicate digestive systems, but with safe and tasty treats you may just win yourself a new best friend.