The goal of the methodology consists in familiarizing the professional public with some existing variants of determination and assessment of efficient fibre of fodders for ruminants and in suggesting the methods to be used. The first part of the methodology defines fibre and its functions in nutrition of ruminants. The second part is devoted to the description of the methods of determination and assessment of the physical structure of the fodders. The third part presents some results of our experiments, interpreting the practical use of the suggestions. To assess the structure of the fodder, we recommend separating particles of different size, contained in the native or dried fodder sample, by horizontal or vertical agitation on several sieves. The determination of starch in the remaining fodder passing through a 4.75 mm-mesh sieve serves as base to assess the degree of disruption of the maize grain in the silage, resp. Corn Silage Processing Score (CSPS). The simplest method consists in visual assessment of the grain (of the degree of its disruption) after wet separation in water, or in visual assessment of the food industry products by the degree of their turning to slime.