FIELD: feed industry. SUBSTANCE: invention relates to dry feeds for dogs and cats and its objective is to reduce time on sampling, to examine samples by standard techniques, and to develop common calibration equations for analyzing dog and cat dry feeds for all quality characteristics simultaneously. For that, dry dog and cat feed samples from different countries- manufacturers. Average sample is prepared from general sample taking into account color, shape, and dimensions of granules. Each sample, after grinding, is characterized by diffusion reflection spectrum registered on IR analyzer and, simultaneously, standard chemical methods are utilized to find level of nitrogen, which data are further used to calculate contents of "crude" protein, "crude" cellulose, "crude" fat, "crude" ashes, calcium, phosphorus, salt, and moisture. Spectrum of each sample is completed by quality data and common calibration equations are solved by fractional least-squares method involving second derivatives to find optimal wavelengths and coefficients for each of 8 quality characteristics. EFFECT: improved evaluation accuracy. 2 cl, 1 tbl
