[Level of free amino acids in the milk of cows in relation to values in arterial and venous blood].

The levels of free amino acids in cow's milk vary greatly. The highest value of 164.484 mumol/l was recorded in glutamic acid, followed by glycine, alanine, lysine, and the lowest values were found in cystine, methionine, phenylalanine, tyrosine and isoleucine (5--10 mumol/l). The levels of free amino acids in milk and their order differ from the values and the order in blood. For a large proportion of free amino acids, significant to highly significant relations exist between the levels in arterial blood and venous blood before and after milking. On the other hand, significant positive correlations were found only between the level of cystine in arterial blood and in venous blood after milking, between threonine level in arterial blood and in venous blood before milking, and a highly significant negative correlation was recorded between the leucine level in venous blood before milking and the respective value in milk.