EN
The studies have been carried out on 200 chickens, Astra В cross-breeding, in the period from 1 to 49 days of breeding. The birds were divided into two groups. The control group was given feed with the addition of ground maize and an increased amount of ground wheat. The energetic value of the mash was increased by the addition of bone fat in the amount of 3,5°/o (up to three weeks) and 6Vo after four weeks of breeding. There were evalueted: haematocrite, level of haemoglobin, number of erythrocytes and leucocytes, activity of AspAT and A1AT, basic phosphatase, total protein, cholesterol, Ca and P in the serum. The introduced amounts of bone fat to feed did not cause any disturbances in digestion, and did not influence significantly the haematological and biochemical indices. Only a drop of the activity of AspAT and a variable activity of A1AT, and an increase of the content of cholesterol were observed in the serum.