The aim of this experiment was to establish mathematical equations to be used for estimation of the some bio-productive and physiological indices according to the non-starch polysaccharides (NSP) of the wheat-based compound feed, as well as according to the intestinal viscosity. The experiment was carried out during six weeks, on 120 Ross 308 hybrid chicken, divided into four experimental groups (LM, LE1, LE2, and LE3). Chickens in the four experimental groups were fed as follows: during the first rearing period, from hatching to 3 weeks of age, the compound feed provided 3117-3175 kcal ME and 22.26-22.69% CP, and during the second rearing period, from 4 to 6 weeks of age, the compound feed provided 3161-3212 kcal ME and 19.99-20.16% CP. The difference among experimental groups was the wheat proportion in the compound feed structure that varied between 0 and 40% during the whole rearing period of broilers, from hatching to 6 weeks of age. Based on the experimental data obtained and using the Data Fit software the mathematical equations for estimating the main nutritive and bio-productive indices were determined. Thus, the body weight at 3 weeks of age could be predicted with the following equation y=a+b*x*ln(x)+c*x 2.5, correlation coefficient between body weight and soluble NSP content being -0.93146, body weight at 6 weeks of age could be predicted with the equation y = a+b*ln(x)/x+c/x2, correlation coefficient between body weight and soluble NSP content being -0.822, feed conversion ratio could be predicted with the equation y=a+b*x*ln(x)+c*exp(x)¸ a negative correlation being found between the feed conversion ratio and NSP content, r=-0.7285.