Horses can normally eat 1.5-2% of their body weight in hay, which equates to 18-24 lbs. of hay per day. The quality of the hay will determine how much is needed and if supplemental grain should be added. Good alfalfa can be 18-20% protein and 55% TDN or energy. Alfalfa is also very high in calcium (5 to 1 Ca/P ratio). Most good grass hay (oat and rye) is 10-12% protein and 45% TDN and will have a 2 to 1 Ca/P ratio. Horses also have a fiber requirement and tend to get bored when roughage (hay) is limited. The amount and type of hay fed relates to the other feeds you use and the use of your horse. In general, feed hay twice a day; limit alfalfa to one-half of your roughage; and feed grain according to body condition and use of the horse. Always have your hay analyzed so you can match the grain supplementation to your horse’s needs.