Why it matters: Well, it matters a lot if you are a horse.
The main difference is that you, or rather more likely, horses eat hay. Straw is not for eating. Hay happens when green grass goes a long time without being cut, and then is harvested and dried. It has a lot of nutrients in it, which makes it a good food for horses. Straw, on the other hand, has little nutritional value, and is simply the stalk part of grain. When grain is harvested, the top seedy, nutritional part is used in all sorts of food, but the stalk is separated, and that is straw. Straw can be used in bedding for livestock and in autumnal tractor rides, followed by cider and donuts, if you are lucky. So really a hay ride should be called a straw ride....
