Hay Analysis
Is your hay meeting your horses’ needs?
By Dr. Barbara Jones

While hay is a stable of all horses’ diets, for at least part of the year, it does not always receive the same scrutiny as other parts of the diet. To make matters more complicated, there are many factors that influence the nutritional value of hay; such as the species (alfalfa, various grasses or clovers), the climate, the weather pattern, the soil, and the stage of maturity.  This means that no load of hay has the same nutritional composition, even if you bale and store your own hay every year.  All of these factors only reinforce the importance of getting a hay analysis done.

The information provided by a hay analysis allows a ration to be individualized to each horse; taking into account the variation in nutritional requirements that are dependent on a horse’s growth stage, activity level, and potential disease state, such as equine metabolic disease.  Most importantly, knowing what is in your horse’s hay allows you to determine whether or not he needs supplements at all, and if he does, tailoring his supplements to the hay.

So what is hay analysis? A hay analysis is an overall evaluation of how well the hay meets the horse’s needs, especially in regards to energy and nutrients. There are several steps in obtaining a hay analysis. First of all, a core sample must be taken, which can be done by an agronomist, by an employee of a forage testing center, or by you. Each sample of hay is actually a set of approximately 20 cores taken from the same hay batch, ie same location (field or farm), cutting, maturity, and composition (grass, legumes, weeds), but different bales within that batch. 

If you are taking a sample to submit to a lab, it is important to known the accuracy of a hay evaluation depends on the whether the hay samples are from the same location, the same cutting, the same plant maturity, and the same composition. The analysis will average the samples from the different bales of the same batch. This means that several sets of samples from different fields/cuttings/etc may need to be sent to a forage testing center. 

A hay sample requires a core of hay taken with a core sampler/hay probe. If you contact a forage testing center, they will bring one out to take the samples; however if you want to take samples yourself, they are also available to purchase online. The following website, www.foragetesting.org, provides information and diagrams how to sample hay as well as what to look for in a hay probe and a list of all certified labs.

Hay should be tested as close to when it is going to be used as possible. If hay is going to be stored, it is best to wait to test it until it is about to be used due to the nutrient loss that occurs during storage. For example, alfalfa hay can lose up to 73% of its Vitamin E content in 3 months of storage (Lynch, 1996). That is just one example of why it is important to get your hay analyzed to determine whether it is meeting your horses requirements for energy and nutrients!

If you get your hay analyzed, there are resources for understanding the report on the following website: http://www.uwex.edu/ces/crops/uwforage/Feeding.htm or your veterinarian can help you go through the analysis and make recommendations for any supplements.

The following are commercial testing labs located in Wisconsin:

• AgSource Cooperative Services
  Bonduel, WI
  phone: 715-758-2178 fax: 715-758-2620
  http://agsource.crinet.com
  Steve Peterson speterson@agsource.com
  Doug Harland dharland@agsource.com
• Dairyland Laboratories, Inc. 
  Arcadia, WI
  phone: 608-323-2123 fax: 608-323-2184
  http://dairylandlabs.com/
  Dave Taysom dtaysom@dairylandlabs.com
  Jerry Dekan jdekan@dairylandlabs.com
• Rock River Laboratory, Inc.
  Watertown, WI
  phone: 920-261-0446 fax: 920-261-1365
  http://www.rockriverlab.com
  Don Meyer don_meyer@rockriverlab.com
• University of Wisconsin Soil & Forage Lab
  Marshfield, WI
  phone: 715-387-2523 fax: 715-387-1723
  http://uwlab.dyndns.org/marshfield/
  John Peters jbpeter1@wisc.edu
  Lisa Bauman lbauman@wisc.edu

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References
Lynch, G. L. 1996. Natural occurrence and content of vitamin E in feedstuffs.  Animal Nutrition and Management, M. B. Coelho, ed. Mount Olive, NJ: BASF. P 51.