How to Analyze Feed and Forage Sampling for Horses

Ann Swinker, PhD,  Associate Professor Equine Science

The first half, the laboratory analytical results requires a lot of science.  Remember, the lab analysis of your feed is only as good as the sample you submit.  Collecting a representative sample is the first step of the analytical process.  Following recommended sampling procedures will help insure that your results truly reflect the nutrient composition of your sample.

Hay – Hays of different types, cuttings or lots should be sampled separately. Using a Penn State Forage Sampler (or other suitable hay probe), bore 12 – 20 bales selected at random. Combine all core samples and submit for analysis.  For more information: http://www.extension.org/pages/13009/hay-analysis:-its-importance-and-interpretation
http://www.equi-analytical.com/TakingASample/TakingAHaySample.pdf

Pasture – randomly select 12 to 20 sites where the animals have been grazing and clip the forage at grazing height. All subsamples should be combined and thoroughly mixed in a clean plastic bucket to form a composite sample. Take a one pound (0.5 kg) composite sample, pack tightly in a plastic bag and freeze for 12 hours prior to submitting for analysis. Freezing will help prevent marked chemical changes due to respiration or fermentation.

Grains and Ingredients – Bin storage: randomly collect 12 to 20 samples as the grain is discharged and combine in a clean plastic bucket. Thoroughly blend and submit about one pound (0.5 kg) sample for analysis.

Generally, analysis can be as little as $10 for an individual nutrient and as much as $80 for analysis of 30 nutrients. The most common nutrients analyzed include crude protein, fat, soluble carbohydrates, fiber, and the minerals calcium, phosphorus, potassium, magnesium, sulfur, copper, zinc, and selenium.  The crude protein content measurement gives an estimate of a feed's protein content, but it doesn't give much information on the quality of the protein. Fat is a nutrient that provides energy, as do soluble carbohydrates. Soluble carbohydrates can be analyzed as water-soluble carbohydrates, ethanol-soluble carbohydrates, fructan, and starch, and this analysis is important for horses with a variety of disorders (such as equine metabolic syndrome, laminitis, or equine polysaccharide storage myopathy). The two most common fiber analyses are for acid detergent fiber (ADF) and neutral detergent fiber (NDF), which can be used to estimate forage quality.

The Analytical results are reported on both an as sampled and dry matter basis. Either can be used for ration balancing and it is important to understand the difference between them and how each can be used most effectively. The important point is to be consistent. When developing a ration or comparing different feeds, the results need to be compared on the same basis. Failure to do this will result in improper formulation.

For a laboratory near you contact your county Extension office.  Companies such as Equi-Analytical (www.equi-analytical.com), Holmes Laboratory Inc. (www.holmeslab.com), or Dairy One (www.DairyOne.com) for grain and forage analysis. These companies provide information on their websites about how to collect samples, and they can provide prepaid packaging for sending samples to their laboratory for analysis.

Reference
National Research Council (NRC). 2007. Nutrient Requirements of Horses, 6th Revised Edition. The National Academies Press, 500 Fifth Street N.W., Washington, D.C. 20001.
http://www.nap.edu/catalog.php?record_id=1213

Equi-analytical laboratories, Ithaca, NY http://www.equi-analytical.com/default.htm

Janice Holland, Analyzing Feed and forage for Horses, TheHorse.com, 2010, http://www.thehorse.com/ViewArticle.aspx?ID=17666&src=bio