1. Institute of Animal Physiology, Centre of Biosciences of the Slovak Academy of Sciences , Šoltésovej 4-6 , Košice , Slovakia
2. Department of Animal Nutrition, National Agricultural and Food Centre , Hlohovecká 2, 95141 Nitra-Lužianky , Slovakia
3. The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences , Instytucka 3 , Jabłonna , Poland