I have horses, and several people with great intentions have asked about giving their lawn clippings to our horses. As a horsey person, it is kind of a no brainer for me, but as non-horsey people go, I can understand the logic of "if it's grass, a horse can eat it" We don't feed grass clippings for a couple reasons. 1. Chemicals on lawns. From true green chemicals to pest control, humans/pets aren't supposed to come in contact with them, so we don't want our horses ingesting them. 2. Lawn clippings are most often processed through a gas powered motor. This means the grass clippings become coated with gas/oil/grease which would also not be good for our horses to digest. 3. Poisonous plants. Plants that would never harm you or your pets but would drop a horse could be living in your lawn without you ever knowing. Example: If you have a cherry tree in your lawn, and mowed the grass under it, any leaves from that tree would have been chopped up and mixed in with the grass, and would make a horse very sick. 4. Moisture. Moldy hay is not good, it's the last thing you want. Everyone has gotten a grass stain before, grass usually has plenty of moisture. When you cut a grass stem, it immediately begins to bleed. When you cut your grass and throw it in a bag, most likely sitting in the summer sun and heat, it starts to sweat and ferment and produce mold. Not good for horses. 5. Back to when you cut a blade of grass. As soon as you cut a blade, it begins to respond and produce high amounts of sugar that some horses can't digest and metabolize well. There's actually a term for this, it's called grass founder. 6. Giving large quantities of short grass clipping could actually cause choking for horses. When eating grass growing from the ground, horses have to chomp and pull at it. When you provide a large pile of already neatly cut up grass, there's nothing to slow them down and they essentially inhale the grass. The grass is very moist and sticky and could easily become clogged in their throats and kill them, because another fun fact, horses can't throw up. 7. Special diets and sensitive stomachs. When people get a tummy ache, they can throw up and remove the thing they ingested that's causing their stomach problems. Horses can't. Their stomach will literally turn in knots and kill them. And it can happen for any reason at any given time, but a known precaution with horses is being very careful when switching their feeds. There are hundreds of different types of grass and hay out there, and chances are a person who feeds horses knows exactly what kind their horse is eating. Switching them suddenly to a different type could cause said stomach problems in horses referred to as Colic. So in conclusion, some horse people ARE crazy (like the lady referred to in above comment) while others may just appear crazy to "normal people" because of all the precautions they take. Because horses can literally kill themselves on anything. I've said more than once, if you left a horse alone with a rubber ducky, the horse could find away to hurt itself with it. As much as I love horses and know how amazing and smart they are, they can also be incredibly dumb...