1 Department of Animal Nutrition and Forage Production, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno, Czech Republic, European Union 2 Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno, Czech Republic, European Union 3 Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ616 00 Brno, Czech Republic, European Union 4 Department of Languages, Faculty of Regional Development and International Studies Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno, Czech Republic European Union * E-mail: kizek@sci.muni.cz