1. Institute of Animal Physiology; Slovak Academy of Sciences; Šoltésovej 4-6 Košice 040 01 Slovakia
2. University of Veterinary Medicine and Pharmacy; Komenského 73 Košice 041 83 Slovakia
3. Department of Environmental Protection Engineering Faculty of Technology; Tomáš Bat'a University in Zlín; T.G. Masaryka 5555 Zlín 760 01 Czech Republic
4. Department of Nutrition; National Agricultural and Food Centre; Hlohovecká 2 Nitra-Lužianky 7949 41 Slovakia