These are carbohydrates from the cell contents as opposed to the cell walls of plants and comprise mostly starch and sugars. The NSC can be further sub divided into Water Soluble Carbohydrates (WSC = sugars and Fructan) and Ethanol Soluble Carbohydrates (ESC= sugars), and Starch.
NSC is an important measurement because the NSC content has a marked impact on the amount of simple sugars (glucose) entering the blood following a meal, and as a consequence of that, the insulin response. High NSC values provoke a more marked insulin response in normal animals but in those suffering Insulin Resistance, Cushings Disease and those prone to Laminitis, a high NSC meal may cause increased risk of disease or exacerbate existing disease conditions.
Examples of high NSC feeds include starchy grains such as corn, oats, barley, sorghum, wheat, molasses, and potentially some grass hays. Many agricultural grass species were developed to feed cattle and sheep and a high energy content from NSC was desirable. Low NSC feeds tend to be those high in fiber, NDF and ADF such as sugar beet pulp, soy hulls, lupin hulls and some hay, particularly Lucerne. Assessment of forage feed NSC content can only be done by laboratory analysis. Soaking hay in tepid water for 30 minutes leaches out some of the soluble sugars and helps to reduce the NSC content so this is commonly done for horses at risk.