RT Journal Article SR Electronic A1 Veselý, Pavel T1 Dynamic contents of energy and organic nutrient in steppe growths of the Mohelenská Serpentine Steppe National Nature Reserve JF Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis YR 2014 VO 54 IS 4 SP 117 OP 130 DO 10.11118/actaun200654040117 UL https://acta.mendelu.cz/artkey/acu-200604-0015.php AB The aim of the study was to determine the dynamics in the content of organic nutrients, ash and energy in dry matter of growths within the Mohelenská Serpentine Steppe National Nature Reserve (NPR), and to document their initial nutritive value before the intended grazing. Plant samples in 1995 and 1996 during the growing season in 14-days intervals from the area of 3 × 1 m<sup>2</sup>. Amounts of dry matter, fibre, nitrogen substances, fat and ashes were determined in growths according to the ANONYM (2001). Nitrogen-free extract substances (BNLV) were determined by final calculating; BE, ME, NEL, NEV, PDIN and PDIE were calculated using the regression equations (VESELÝ and ZEMAN, 1995, 1997).Combining ratio (SP) was calculated according to the relation: SP = PDIN (g)/NEL (MJ). The dynamics of the contents of dry matter, organic nutrients, ashes and energy were assessed in the growth during the vegetation period and the dynamics was compared with standardized requirements of sheep (no pregnant ewe). Regression and correlation relations for nutrition value of the growths during vegetation period were calculated by use of mathematical-statistical analysis. Only statistically significantly (P