H. Lukanov1*, I. Pavlova2 1Department of Animal Science – monogastric and other animals, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria 2Department of General livestock breeding, Faculty of Veterinary medicine, Trakia University, 6000 Stara Zagora, Bulgar

R. Otuzbirov, R. Kalev, Zh. Gergovska Two group production experiments were carried out with a total number of 24 Black and White male calves. The animals were divided in three groups with 8 calves in each depending on the housing and feeding conditions: free indoor housing in box (gr