This International Standard specifies a method for the polarimetric determination of the starch content of animal feeding stuffs and raw materials for animal feeding stuffs. The method is not applicable to products which, besides starch, contain other substances which are optically active during the analysis and do not dissolve in 40 % ethanol. Examples of these products are potato pulp, beet chips, beet leaves, beet tops, yeast, soya products, lupine and products rich in inulin (e.g. chicory roots and Jerusalem artichokes). In these cases an enzymatic determination of the starch content may be used. This method is not applicable for the quantification of starch with an amylose content exceeding 40 % (e.g. high amylose maize starch like Hylon VII). CAUTION — Depending on the intensity of the heat/moisture treatment the product has been subjected to, too low a starch content may be determined.