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Starches and Sugars in Horse Feeds

horse feed

Frequently, when people ask about “low-carb” diets, they’re really asking about low non-structural carbohydrate (NSC) diets. Non-structural carbohydrates (NSC), which include sugars and starches, are useful nutrients because they can be broken down and absorbed in the small intestine and stored as glycogen in the muscles and liver. This means they can be accumulated and readily mobilized to provide energy.

Nutrena uses the term "controlled" instead of "low" because performance horses require more starch and sugar in their diets in order to recover from exercise.

Controlling NSC intake is vital for the well-being and performance of horses. Starches and sugars are required for energy and glycogen repletion. However, overloading the digestive system with NSC can result in metabolic disturbances, which may lead to problems such as colic, laminitis (founder), obesity, or developmental orthopedic disease.

Because performance horses require sustained energy, low-carbohydrate diets are unsuitable. However, controlling starch and sugar intake can be beneficial depending on age, breed, activity, metabolic conditions and physical state.

Nutrena’s nutrient-focused approach allows horse owners to provide a controlled glycemic response while maintaining appropriate levels of starches and sugars.

The Benefits of a Controlled Starch Formula

Starch is a great energy source for most horses, but excess starch can cause metabolic disturbances, such as colic or laminitis in horses. When fed properly, a controlled starch product ensures that specific starch fractions are digested throughout the intestinal tract, which provides the energy a horse needs without the risk of excess starch leaking into the hindgut.

What makes up NSC and why is it important?

NSC stands for ‘non-structural carbohydrates’ and is typically the combination of starch and sugar. Horses with metabolic concerns, such as Cushing’s disease, laminitis or Polysaccharide Storage Myopathy (PSSM) require reduced levels of NSC to support their activity levels. Fructan is also included in NSC, but is typically found in forage products, such as grass or hay.

Starches and sugars are broken down in the small intestine. Sugars and some starches are digested rapidly, while other starches may digest more slowly because of the plant’s structure they are derived from. Because horses cannot tolerate large intakes of NSC in one meal, they must be controlled in the diet.

Low Starch Feeds

Most horses do great with a moderate level of starch in their feed however some horses have metabolic conditions, such as EMS, Insulin resistance or laminitis, which require a reduced starch level in the total diet. SafeChoice® Special Care is considered a low-starch feed with a maximum starch level of 13%. To truly provide a low starch and sugar diet, it is important to take into consideration the starch and sugar levels of the forage in the diet.


What does the starch % mean to my horse?

The percentage of starch only tells half the story. When comparing starch intake for horses, it is important to factor in the recommended feeding rate.

% of Starch * Feeding Rate (in pounds) * 454 grams/pound = Grams starch/meal

For example:

A). Feed A has 10% starch and a feeding rate of 6 pounds per day: (0.10 * 6 * 454) = 272.4 grams of starch per meal

B). Feed B has 11% starch and a feeding rate of 3 pounds per day: (0.11 * 3 * 454) = 149.82 grams of starch per meal

In this example, the feed with the higher starch percentage on the tag actually delivers less starch per meal, when fed to the feeding directions.

NSC Content in Feed

Location of NSC Listing:

NSC levels in feeds can be found in a variety of locations, on manufacturer websites, brochures and listed on feed tags and bags.

Regulated NSC (dietary starch and sugar) values are often listed on feed tags. Feed tags are approved by individual states and most follow recommendations given by AAFCO (American Association of Feed Control Officials). On most state feed tags, where the feed does not contain cool season grass, NSCs are listed individually as dietary starch and sugar. These dietary starch and sugar guarantees are generally required if the bag or marketing material makes any reference to these nutrients.

Definition of Level Listed:

Once you note the location you are pulling the values from, it’s important to determine what the definition of the reported value is. NSC may be listed with no notation, or as an “average”, a “minimum” or a “maximum”. When evaluating dietary NSC content for horses with a specific metabolic condition, controlling the NSC in the total diet (forage + concentrate + treats and supplements) and understanding maximum levels is important. The maximum level indicates that the dietary starch and sugar level does not exceed the level listed but could be lower. If a minimum level is listed, that number means that the NSC content could be higher than the listed value, but not any lower. If a value is simply listed with no notation, that may represent a single analysis that was sent to a lab; however no minimum or maximum is assured from bag to bag and levels could either exceed or fall below that listed value, providing little guidance as to the appropriateness of that feed for your horse over time.

Analytical and Natural Variation:

Keep in mind that even though the same ingredients are used in a feed, NSC content of those specific ingredients can vary over time or by delivery load, based on supplier, plant maturity at harvest, weather conditions, etc. Premium manufacturers will have ingredient analysis protocols in place to monitor and manage this variation potential. The highest confidence rating of an NSC value comes from a feed tag printed on the bag or attached to a bag, that specifically lists maximum values of the dietary starch and sugar components of NSC.

When feeding horses who are sensitive to the NSC content in their total diet, confidence in what you recommend is of utmost importance. Feeds displaying a maximum dietary starch and maximum sugar content on the actual feed tag are going to provide that assurance.