1. 1Department of Animal Science University of Pannonia, Deák F. u. 16, H-8361 Keszthely, Hungary
2. 2Department and Clinic of Obstetrics and Reproduction, Faculty of Veterinary Science, Szent István University, Budapest, Hungary
3. 3Department of Economic Methodology, Georgikon Faculty, University of Pannonia, Deák F. u. 16, H-8361 Keszthely, Hungary