Understanding Hay Quality – Part III

So far in our three-part series on hay quality we have looked at defining terms, quality standards, maturity, species and variety, leafiness, and harvesting. In our last installment, we’re look at how to meet our horses nutritional needs with hay, testing forage for nutritional value, and purchasing hay. For more information on any of these topics, visit For more information visit Purdue University’s Hay Information Page, which is source of the information below.
50 percent to 100 percent of the horse’s nutrients can be supplied by hay depending on on use and nutritional classification. There are 5 nutritional classes for horses:

  1. Maintenance: Mature horses that are maintaining body weight and are not pregnant, lactating, breeding nor being exercised. This class of horse can often meet all of its requirements with forage.
  2. Pregnancy: For the first eight months of pregnancy the nutritional are the same as for a mare being maintained. During the ninth, tenth, and eleventh months of pregnancy, the energy requirements increase 11 percent, 13 percent, and 20 percent respectively.
  3. Lactation: During the first three months after foaling, mares can produce milk equivalent to 3 percent of their body weight per day and 2 percent per day during months four to six. The requirements for energy are about 80 percent above maintenance for the first three months and 50 percent above maintenance for the next three months of lactation.
  4. Growth: Growing foals require feeds of higher quality than what mature horses require. The age of the foal and the average daily gain determine the requirements. Horses are still growing past 24 months of age, and longer in the slower maturing breeds. The optimum growth rate has not been established, but overfeeding can cause developmental orthopedic diseases and underfeeding can cause permanent stunting.
  5. Work: The level of exercise or work the horse is doing determines the amount of nutrients needed. Energy is the fuel for work, and as the intensity or duration of the work increases from light to moderate to intense, the requirement for energy increases 25 percent, 50 percent and 100 percent above maintenance, respectively.

What you feed your horses should be calculated consider that they will eat only about 2.5 percent of their body weight everyday in dry matter and should consider the quality of the forage fed. Mature forages with high NDF values limit intake and require that more nutrients be provided in the form of concentrate supplements.
Forage Testing
Forage testing helps take the guesswork out of finding the right hay for your horses. There are currently three methods of testing:

  1. Square_hay_bales_1Visual appraisal: Oldest and most used method. Useful for finding foreign matter, finding dust, determining leafiness, and looking for color but overall a very subjective way of evaluating hay quality.
  2. Chemical analysis: Can be costly, but is the most accurate way to determine hay quality.
  3. Near Infrared Reflectance Spectroscopy (NIRS): Quicker and less expensive method to determine the major chemical constituents in forages. Forage can be analyzed in less than ten minutes.

Hay should be purchased and sold by weight rather than by volume. There is a big difference between a 40lb bale and and 80lb bale. As mentioned earlier, a horse will only consume 2.5 percent of his body weight per day. If a 1,000 horse consumes 25lbs of a 40lb bale, he’s consumed 62.5% of the bale. If he eats 25lbs of a 80lb bale, that’s 31.3% of the bale.
You should also request to see testing results to confirm the quality of the hay you’re purchasing. Keep in mind that what you’re really purchasing is nutrients rather than a bale of hay. It makes sense to pay a higher price for proven quality, because you want to ensure that the hay your horse consumes provides the appropriate nutrients to maintain his weight and health.

Leave a Reply

Your email address will not be published. Required fields are marked *