Simple sugars are produced by plants and comprise either monosaccharides like glucose, fructose, and galactose or disaccharides with two monosaccharides chemically bonded together like sucrose which contains glucose and fructose units, or lactose (milk sugar) made from glucose and galactose. Simple sugars are a readily available energy source rapidly absorbed in the small intestine.
Other, more complex sugars like Fructan contain chains of monosaccharide units and contribute to the Non Structural Carbohydrate fraction NSC of plants which may have implications for horses prone to Laminitis, Cushings Syndrome, and Insulin Resistance.
Two measures of sugars are used in feed analysis.
The Water Soluble Carbohydrates WSC includes simple sugars plus fructan
The Ethanol Soluble Carbohydrates ESC includes the simple sugars only
Fructan can be estimated by subtracting the ESC value from the WSC value