You will hear a lot of things when it comes to feeding horses and it can be confusing, especially for the first time horse owners. Some of these things have been passed down from generation to generation some are useful while others are outdated and won't apply to your horse now.
Myth #1: Bran mash is good for a horses digestion
Fact: Although they love the taste and their manure becomes softer it is not good for them. Bran is nothing more than an intestinal irritant, not a laxative and is high in phytates which will block calcium. It has ten times more phosphorus than calcium and with that out of balance ration it can lead to poor muscle contraction/relaxation and porous bones. You would be better off feeding your horse soaked hay pellets.
Myth #2: Horses need grain
Fact: Mature horses that are not being worked or that are being lightly ridden are unlikely to need grain. Those that probably need the extra energy that grain provides is nursing broodmares, racehorses and those competing in other competitive sports. The most important thing for horses is forage being pasture or hay. Their digestive system was meant to break forages like plants not the high amounts of carbohydrates from grain. Giving high amounts of grain can cause your horse to colic, develop laminitis or ulcers.
Myth #3: Corn or Oats will make my horse hyper or hot
Fact: If you're feeding your horse more than they can burn off through exercise they will have excess energy and will be bouncing off the walls. Corn contains more energy and less fiber per pound than oats, but oats generate more heat units in digestion than corn. Oats, however, contain an alkaloid called avenin, which is a central nervous system stimulant and some horses are sensitive to the avenin. If you feed corn and oats together do a half and half mixture and go by weight not volume.
Myth #4: Feeding your horse off of the ground is better
Fact: Horses were meant to eat off of the ground and not fed in elevated feeders. When you feed your horse in an elevated feeder they won't chew their food properly as the lower jaw is meant to slide forward into the grinding position which happens when the head is down. Horses fed in elevated feeders will have improper tooth wear, increased risk of choke, and respiratory issues from inhaling the dust and mold in the hay and grain.
Myth #5: Pellets cause horses to choke
Fact: Pellets in general do not cause a horse to choke its behavior problems that cause the choke. I've seen horses choke on hay, large cubes, apples, carrots and other treats. Choke is caused from horses that bolt their food down because they are aggressive eaters. Some of the things you can do to help with this are putting large rocks in a shallow feed pan, giving smaller portions or increasing grazing time.