Corn is a popular feed due to its ready availability. Many horse owners prefer not to feed corn because they feel it is too "hot" a food (that is, too high in energy). Although corn does contain twice as much energy as an equal volume of oats, when both corn and oats are fed by weight to provide equal amounts of energy, corn does not have a greater tendency to make a horse more high-spirited than do oats. Corn is palatable, consistent in quality, and is the only common grain that has significant vitamin A. Corn can be fed whole, cracked, or by the ear. It should not be ground finely, because it becomes dusty.
From this book: http://www.amazon.com/Horse-Owners-Veterinary-Handbook-Thomas/dp/0470126795/ref=sr_1_1?ie=UTF8&s=books&qid=1276823593&sr=1-1
^ Doesn't mention that corn is one of the hardest grains for horses to digest as it has really high levels of starch and sugar - Making it a trigger for things like Tying up, Insulin Resistance and Laminitis.
LOL, too true!!! Again not directed at you Ricci or anyone else specific. Sometimes I read a question and I know the answer, but just can't muster the energy to explain it all. Good thing I didn't do that in school, right?
Haha, don't worry, I'm not offended. =] I feel the same way sometimes. I know they say there are no stupid questions, but sometimes.... haha. And like you two, I feel the need to point out this is not directed at anyone in particular, and no one on this thread. =]
You're right though, it doesn't say anything about starch and sugar. It goes on later about moldy corn poisoning, but that's it. Although, there is a rather large section about how much of what they should get. Since starch isn't on there, perhaps they shouldn't be getting it? Lol.
Horses aren't designed to digest starch how it is found in grains - There is a pocket of starch that protects the goodies inside. It's the grains natural defense, but it is also what causes so many issues in the horses gut. They have to get through all that starch to get to the nutritional goodness - And what they don't get through ferments in the hind gut and effects the acidity.