Hay Quality

• Smell the hay to be sure it is fresh and free from mold and dust, which can cause digestive or respiratory problems. Look at the appearance of the hay: It should have a high leaf to stem ratio, since the protein and nutrition of hay is mainly in the leaves. In addition, stemmy hay is difficult to chew. Lastly, check the hay for color and cleanliness. It should be green and bright, which means it contains carotene--vitamin A. Hay that is contaminated with weeds, dirt, or debris is not good quality hay. High quality hay contains more nutrients and is less likely to cause colic from impactions than poor quality hay.
  
  

Harvest Time

• The time of year in which the hay is harvested and the maturity of the crop affects its quality. Hay harvested before it blooms is typically more tender with a greater amount of leaves and a higher protein percentage. Hay harvested in the spring, first cutting, is easier for a horse to digest. It is tender and generally contains more leaves. Digestibility declines in hay that is cut in July to August, second cutting. However, the third cutting, hay harvested in the fall, contains more nutrition than second cutting hay.
  
  

Roughage Requirements

• The amount of roughage needed in a horse's diet depends on whether the horse is fed any supplemental feed, such as grain. According to the Texas A&M Department of Animal Science, Equine Division, a mature performance horse can consume 1.6 to 2.3 tons of hay per year. Typically, a horse needs one percent of his body weight in roughage. To figure a horse's body weight take his heart girth--measurement around the horse's abdomen at the withers--twice, times his body length--point of front shoulder to the point of his buttocks, divided by 330. For mares that are nursing and weanlings--foals who have just been weaned from their mother--this amount can go as high as two to three percent of body weight.
  
  

Alfalfa Hay

• Alfalfa is one type of legume hay, which is richer in Vitamin A, vitamin E, protein, fiber and calcium than grass hay. However, overfeeding alfalfa hay can cause digestive problems and bloat. If the rumen becomes too full of gas (bloat), it expands and puts pressure on the animal's lungs and large internal blood vessels, causing it to die. Additionally, alfalfa hay becomes moldy more readily than grass hay if it gets wet or is baled when it is too green.
  
  

Grass Hay

• Grass hays generally contain eight to 15 percent protein, considerably less than that of alfalfa. Since grass hays contain a lower amount of protein and fiber, they are safe to feed "free choice" to horses with little worry of digestive problems. It is still important to check the quality of the hay; it should be leafy, clean, bright green and pliable. The most popular grass hays fed to horses are timothy, Bermuda, and orchard grass.