Newsletter March 2016

Dear Horse lover,

It has been an exciting few months since my book 'Natural Feeding for Horses' came out. More and more people switch to more roughage-based diets to cover their horses' nutritional requirements. Good news for happy tummies!

By focussing a diet more on roughage, it is essential to know what roughage provides to your horse. The most accurate way to discover the nutritional content of your roughage is by having it analysed. Sally Flis of Equi-Analytical (US) has contributed a feature to this newsletter on what a roughage analysis tells you. Equi-Analytical is part of Dairy One and has laboratories in many countries around the world that offer roughage analyses.

Alex and Sensation

In the next mailing I will explain how a roughage analysis can be used in the Natural Feeding system. I will also address the concerns of one horse owner who asks whether a roughage-only diet would be suitable for her horse. If you have any nutrition-related questions that you feel could be answered in the newsletter, please send them in and they might feature!

Have a wonderful time,


Secrets of Roughage Analysis

By: Sally Flis, Ph.D. – Feed and Crop Support Specialist, Dairy One

Testing your roughage is the best way to know if it is meeting your horse’s needs for energy, protein, and minerals. Roughage analysis includes moisture, fiber, protein, sugars, starches, and minerals. Roughages should be tested when horses are introduced to new hay, new pastures, moved to a new stable or when purchasing hay.

Depending on the analysis package you select, your results will have between 13 and 26 values that describe the roughage you are feeding. In this article I will cover what some of the components are and why they are important.

A roughage analysis is the most reliable way to discover the nutritional value of your roughage.

A roughage analysis is the most reliable way to discover the nutritional value of your roughage.

Crude Protein (CP)

Crude protein is measured as nitrogen in the sample multiplied by 6.25, because most proteins contain on average 16% nitrogen. Protein is necessary for the growth and maintenance. In horses protein is broken down to amino acids in the small intestine and the cells of the body use the amino acids to rebuild muscle, hair and hooves.

Acid Detergent Fiber (ADF)

A measure of the least digestible plant components, including cellulose and lignin. ADF values are inversely related to digestibility and energy. Forages with low ADF concentrations are usually higher in energy.

Neutral Detergent Fiber (NDF)

The measure of all the fiber in the plant: hemicellulose, cellulose, and lignin. The measure of NDF is directly related to the amount of forage that the horse can consume. As NDF increases, intake decreases. Higher NDF forages usually provide less energy.

Water Soluble Carbohydrates (WSC)

Are extracted from feed with water and include simple sugars, disaccharides, oligosaccharides, and some polysaccharides depending on the feed. Fructans are included in WSC. Simple sugars are digested and absorbed in the small intestine and have a significant impact on blood sugar (glycemic response), while fructans are fermented in the large intestine and induce a much smaller response. However, when eaten in large amounts, some fructans have been shown to cause laminitis due to the production of lactic acid and the disruption of the bacterial population in the large intestine.

Ethanol-Soluble Carbohydrates (ESC)

Extracts simple sugars, disaccharides, and oligosaccharides, including some fructans, but should minimize the extraction of polysaccharides. It is a subset of WSC. This fraction is generally used to evaluate one set of carbohydrates in a feed that will induce a high glycemic response.


Starch is the other energy component of the feed that is measured in the lab. Starch is a carbohydrate that is preferentially digested in the small intestine. If starch escapes digestion in the small intestine, it passes through the digestive tract and is fermented in the hind gut. This can lead to lactic acid production and the negative factors associated with it.

Non Fiber Carbohydrates (NFC)

A calculated estimate of carbohydrates, NFC = 100 – crude protein% - NDF% - ash% - crude fat%. Prior to the routine availability of WSC, ESC and starch analyses, it was commonly reported as an estimate of feed carbohydrates. However, as a calculated value it will carry all of the errors of the other measurements. Use WSC, ESC and starch when available to evaluate carbohydrate levels in the diet.

Non Structural Carbohydrates (NSC)

An agronomic term used to describe the carbohydrate content of plants defined as WSC + Starch. Confusion abounds in the reporting and interpretation of NSC and NFC. Although not set in stone, there is general agreement that NSC should be defined as the measured sum of WSC + Starch and NFC as a calculated value determined by difference as described above. In either case, using individual measured values of WSC, ESC and starch are better means of evaluating your horse’s diet.

Calcium (Ca) and Phosphorus (P)

Calcium and phosphorus can be determined by near infrared technology or wet chemistry procedures with acid digestion and plasma spectroscopy. Calcium and phosphorus are both important for bones, muscle function, and energy. The ratio of Ca:P should be close to 2:1 to prevent problems.

Magnesium (Mg), Potassium (K), Sodium (Na), and Chloride (Cl)

Magnesium (Mg), potassium (K), sodium (Na), are determined with wet chemistry procedures with acid digestion and plasma spectroscopy. Chloride (Cl) is determined by a wet chemistry extraction and determination of concentration with a silver electrode. High quality forages are typically adequate in Mg and K. The Na and Cl requirements are met by providing salt. However, a performance horse that sweats a great deal may require K, Na and Cl supplementation to replace excess mineral loss via the sweat.

Iron (Fe), Zinc (Zn), Copper (Cu), Manganese (Mn), and Molybdenum (Mo)

Determined with wet chemistry procedures, these minerals are required in trace amounts and can interfere with other minerals if they are not monitored. For example, very high levels of zinc can interfere with copper utilization, even though copper supply appears adequate.

In closing, fiber and carbohydrate concentrations are determined largely by the stage of maturity of plant. Protein concentrations are influenced by stage of maturity, nitrogen fertilizers, and soil available nitrogen. Mineral concentrations of the plant are directly related to the soil concentrations of minerals and applications from fertilizers and manures. Use routine forage analysis to monitor the quality of your forages and insure that your horse’s diet is well balanced and meeting daily nutrient requirements.

Information on feed composition is available in our Interactive Feed Composition Libraries.


Sally Flis, Ph.D. is the Feed and Crop Support Specialist for the Equi-Analytical Laboratory located in Ithaca, NY. For more information visit

Equi-analytical provides roughage analyses through a network of affiliated laboratories in many countries around the world. In the UK, the laboratory is Sciantec Analytical Services Ltd. Find more laboratories here.

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