STUDY OF THE AMINO ACID PROFILE OF THE HOLSTEIN COW`S MILK OF DOMESTIC REPRODUCTION

Abstract

The uniqueness of milk lies in the fact that it contains protein, the biological
value of which is significantly higher than all known proteins of animal origin. The protein
content of milk is under the control of the genotype of cows, but the degree of realization of
its potential is influenced by the environmental factor. With the intensification of the industry,
the formation of dairy herds in agricultural enterprises is carried out by animals of the Holstein breed. It is relevant to study the quality of milk proteins from Holstein cows produced in
a high-tech dairy complex, which predetermined the purpose of the research. The subject of
the study was the milk of highly productive Holstein cows of domestic reproduction, which
was produced in LLC “Don” of the Voronezh Region. A high concentration of proteins in
milk was noticed, the amino acid structure of which corresponded to cow's milk, which indicated their full value. The complex of essential amino acids contained the most LEU – 8,04 g,
LYS – 6,86 g and VAL – 5,10 g, and to a lesser extent TRP – 0,67 g, MET – 2,11 g and HIS
– 2,15 g per 100 g of protein. In the composition of bioavailable amino acids, as well as in
proteins, LEU – 7,63 g, LYS – 6,24 g, VAL – 4,54 g were most observed, and less – CYS –
0,32 g, TRP – 0,56 g, MET – 2,01 g per 100 g of protein. The calculated values of amino acid
numbers varied in a fairly wide range. The highest value of this indicator was in amino acids
PHE+TYR (149,2–189,2 %), and the lowest was in TRP (65,5–84,3 %). The presence of the
limiting amino acid tryptophan reduces the biological value of milk proteins, limiting their
bioavailability for different population groups to only 65,5–84,3%. The obtained data from
research on the quality of the protein component of milk should be taken into account when
organizing nutrition for highly productive cows.