M. Mekroud1, N. Arzour-Lakehal1, N.A. Ouchene-Khelifi1,2, N. Ouchene1,2*, A. Titi1, A. Mekroud1 1PADESCA laboratory, Institute of Veterinary Sciences, Road of Guelma 25100 El Khroub, University of Mentouri Brothers, Constantine 1, Algeria 2 Institute of Veterinary Sciences, University

V. Koteva1*, S. Kostadinova2 1Institute of Agriculture, 1 Indusrtialna, 8400 Karnobat, Bulgaria 2Department of Agrochemistry and Soil Science, Faculty of Agronomy, Agricultural University, 12 Mendeleev, 4000 Plovdiv, Bulgaria Abstract. This investigation was aimed at determining the c