Suckler calves of the mother cow herd were used for this investigation. Body weight, growth rate and venous blood acid base status, gas content, creatinine, urea, lactate, total protein, albumin, Ca, Mg, Na, K and Cl were measured at 20, 60 and 90 days of postnatal life. Body weight and growth rate showed strong correlations with some blood values especially at 60 and 90 days of age meaning that adaptation is performed successful in some calves and incomplete in others. Disproportionate growth of body parts and the limited oxygen-carrying capacity below the oxygen needs of the tissues may cause the great lactate values in some calves of all age groups.