Horses require a sufficient amount of hay and roughage in their diet. In order to ensure that your horse is receiving the required nutrients, hay is often analyzed for nutrient content and quality. This article explains the two types of hay analysis: visual and chemical.


Having your hay analyzed is a great idea. It is the only way to determine the actual nutrient content of the hay. It is important to know this so that you can be sure your horse is consuming an adequate diet. You may or may not need to feed grain, depending on the quality of your hay. The better the quality of the hay you feed, the less grain you will need to feed. This can be a significant savings.

Two types of analyses can be performed: visual and chemical. If you have already purchased hay, then you have probably performed a visual analysis. Chemical analysis is done when the hay is sampled and the nutrient content of the hay is determined by a laboratory.

In visual analysis, there are several factors that should be considered. These include:

  • Maturity of hay– The more mature, or older, a hay is, the more fiber it contains, and the more stemmy or unpalatable it will become.
  • Leafiness of the hay – The more leaves a hay has, the more nutrients it is likely to contain since nutrients are concentrated in the leaves, where photosynthesis occurs.
  • Color of the hay – Generally the greener, the better but see chart on next page.
  • Odor and condition of the hay – Throw out hay that is musty, dusty or moldy.
  • Presence of foreign materials in the hay – These can be injurious (poisonous plants, wire) or non-injurious (weeds), but either decreases the overall quality of the hay.

In order to have your hay analyzed chemically, you will need to get a hay sample. Use a core sampler and try to sample from at least 20 to 25 different bales. Be sure to penetrate into the center of the bale with the core sampler. If you do not have experience in hay sampling, see your county extension office for information on how to use the core sampler or to borrow one. Mix the samples together and then put them in a tight, clean, plastic bag or the bags that the forage testing lab provides. Mail the bag to the forage testing lab as soon as possible and have it analyzed.

Interpreting Hay Analysis Results

Interpreting your hay analysis results may not be the easiest part of this process. If you cannot determine what the results mean, you may want to consult an extension specialist in forage crops or agronomy at your county extension center, an animal scientist or a county extension agent. Some of the main things to focus on when you see the analysis reports are:

  • Dry Matter (DM)– This tells you how much of the sample is left after water is removed. It is the moisture or dry matter content of the sample. Hay will generally be about 89 percent dry matter or greater.
  • Digestible energy (DE) – This is a measure of the digestible energy in the hay. For a light-working horse, DE should be 20.5 Mcal/day. Hay may have .76 to .94 Mcal/pounds or higher of DE.
  • Total Digestible Nutrients (TDN) – This is a measure of the total digestible nutrients in the hay or its energy value. TDN may be used in place of DE or offered in addition to DE. It may range from 40 to 55 percent.
  • Crude Protein (CP)– This is a measure of the protein concentration of the hay and can range from 6 percent to 8 percent in native grass hays to about 15 percent or higher in high quality legume hays.
  • Neutral Detergent Fiber (NDF) – This is a measure of the plant’s cell wall content, shown as a percent. The higher this is, the less hay the horse will eat.
  • Acid Detergent Fiber (ADF) – This is a measure of the fiber concentration of the hay, shown as a percent. As ADF increases, digestibility and nutrient availability decreases.
  • Non-Structural Carbohydrates (NSC) – This is a measure of the non-structural carbohydrates in the feed. If your horse has Cushing’s disease or is prone to colic or laminitis, you want to select hay with a lower NSC value. Timothy and alfalfa hay may have a 15 percent or 20 percent NSC value, respectively. If you want this analysis done, you should check to see if the lab offers it, as it is not a common analysis at this time.
  • Starch and Sugar– This is a measure of sugars and starches in the feed. You should feed no more than 15 percent of total daily calories from starch and sugar to horses with EPSM (equine polysaccharide storage myopathy) and PSSM (polysaccharide storage myopathy) EPSM is a muscle disease found in over 100 draft breeds that may cause severe weakness and muscle wasting in horses of all ages, poor performance, abnormal hind limb gaits and shivers, in which the muscles keep twitching. PSSM is a muscle disease found in horses with Quarter Horse in their breeding, such as American Quarter Horses, Paints and Appaloosas. Symptoms include reluctance to move, muscle stiffness, sweating, shifting lameness and tremors in the flank area.

Now you know some basics about analyzing hay. Be sure to consult your county extension agents or state specialists for help if you are not sure how to apply these results. By analyzing your hay, you will be able to feed your horse more effectively and efficiently.

Jenifer Nadeau, M.S., Ph.D, Assistant Professor, Equine Extension Specialist, Department of Animal Science


  • National Research Council. Nutrient Requirements of Horses. (1989). National Academy Press, Washington, D.C.
  • Wright, Bob W. Hay, Haylage and Treated Hay for Horses. (Sept. 2004) Online fact sheet. Ontario Ministry of Agriculture and Food.
  • Vough, Lester R. Evaluating Hay Quality (2000). Online fact sheet, FS-644, University of Maryland.