Quality of milk protein component of highly productive Holstein cows of various ecogenesis

This paper presents the results of the evaluation of milk protein complex of Holstein cows from the European Union countries: the Netherlands, Germany and Hungary. A high concentration of proteins and insignificant differences in the profiles of amino acids in the studied milk samples have been established, which may be a sign of a well-formed breed. The amount of non-essential amino acids in milk proteins is significantly higher relative to all essential ones, as a result, the amino acid index was only 0.69-0.71. The values of amino acid numbers of bioavailable amino acids of milk proteins did not significantly differ between the ecogenetic groups of cows, but varied in a fairly wide range relative to the «ideal protein». The limiting amino acid is tryptophan, in particular, it reduces the biological value of proteins, limiting their digestibility to 84.3-85.8%.