Recently, there has been significant interest in the sugar and carbohydrate content of hays. The below analyses can be very useful in helping to select a suitable feed for horses, especially those that show sensitivity to starch and sugar. Some labs are test for the following (may be an additional charge):
Non-fiber Carbohydrate (NFC): is a mathematical estimate of noncell wall (non-fiber) carbohydrates consisting of starch, sugar, pectin and fermentation acids that can serve as energy sources for the animal. Although not always perfect, the NFC value is often used as an indicator of the level of starches and sugar in a forage sample.
Non Structural Carbohydrates (NSC): an analysis of the non structural carbohydrates (starches and sugars) in the forage. Not to be confused with NFC, which is calculated, not actually analyzed for. Since some horses can be very sensitive to dietary starch and sugar (i.e. horses with Cushing's Disease or laminitis), the NSC level can be helpful in selecting hay choices. Hay containing greater than 10% NSC should not be fed to these horses. Unfortunately, neither NFC nor NSC can give an exact measure of fructans, the complex sugar correlated with founder and other horse health issues.
Starch (a sub-component of the NSC): Starch is a good source of energy. However, no more than 15% of total daily calories from starch should be fed to horses diagnosed with PSSM (polysaccharide storage myopathy).
Ethanol Soluble Carbohydrates (ESC): carbohydrates solubilized and extracted in 80% ethanol. Includes primarily monosaccharides (glucose and fructose) and disaccharide. Some forage labs will refer to ESC simply as "Sugar". To read the latest recommendations on equine nutrient requirements, consult the National Research Council's Nutrient Requirements of Horses publication.