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Department of Animal Science, University of Connecticut



Effective Horse Management - First in the Horse Nutrition Series

Hay Analysis: Its Importance and Interpretation



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



            Having your hay analyzed is a great idea.  It is the only way to determine the actual nutrient content of your 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.  This is a visual and chemical analysis.  If you have already purchased hay, then you have probably performed a visual analysis.  Chemical analysis is 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:


Table 1.  Example of stages of maturity of alfalfa hay (NRC 1989)

Stage of maturity

Fiber content


Early bloom


includes many leaves, few stems



includes fewer leaves, increasing stems

Full bloom


Includes most stems








Usually good, this is hay cut at the best time for feeding

Light golden yellow on outside of bale

Sun bleaching

Decreases palatability and carotene (used to make Vitamin A) but not a very serious problem

Yellow throughout bale

Over-mature when cut

Decrease in palatability, horse may not consume this hay

Dark brown or black hay

Exposed to rain, heavy dews, or fog

Decrease in nutrient content due to leaching by moisture, leaf shattering may be present, hay may be harsh and brittle

Brown hay

Mold growth, hay not dry when baled

Musty, moldy odor, flakes may show mold, loss of dry matter, digestible protein, energy, carotene and other vitamins, don’t use this 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 twenty to twenty five different bales.  Be sure to penetrate into the center of the bale with the core sampler.  See your county extension office for information on how to use the core sampler (or to borrow one) if you do not have experience in hay sampling.  Mix the samples together and then put them in a tight, clean, plastic bag or the bags that the forage testing lab provides.  Mail it to the forage testing lab as soon as possible, and have it analyzed by the laboratory.

            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:



Here is what analysis of a good hay should look like:

Hay type






Mid bloom alfalfa


0.94 Mcal/lb




Mid bloom smooth brome


0.85 Mcal/lb




Mid bloom timothy


0.80 Mcal/lb





            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.



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.  Available online at



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