We often feed our horses the old-fashioned way, on grass growing fresh out of the ground. After a brief ride, we turned out two of our geldings. This time of year, most horses at our stable are on supervised turnout for short periods. Our pasture rotations prevent permanent grass damage.
Ramping up exposure in gradual doses helps horses get used to the green stuff, and prevents laminitis, aka: founder. This terrible internal hoof inflammation can kill a horse. Founder is similar to slowly peeling away your fingernail, only you have to support a thousand pounds or more on the fingernail as it tears away. Ouch.
On a less painful note, imagine being forced most of the winter to eat Shredded Wheat™ and then suddenly being offered a salad featuring baby greens and whatever medicinal herbs you can find. Our two guys cantered off, stopped about 50 feet into the pasture and lifted their heads, watching us watch them. They galloped another 50 feet stopped, and plunged their heads into the greenery. For them, this was second heaven. If at all possible, set aside a green patch for your horse, however small, and give them a chance to be well, a horse!
Read about our founder survival tactics: Founder Chronicles