Abstract
In the first study of a series of experiment samples were taken from 11-13th rib of Hungarian Simmental (HS, n=22) and Holstein-Friesian (HF, n=18) cull cows. In the second one, that of females (n=15) and males (n=12) of HF breed was analysed for amino acid composition, and biological value (BV) of proteins. No significant influence of either breed or slaughter weight was established in this study. Thus, the essential amino acid content and biological value of the proteins in Hungarian Simmental breed are practically the same as in the Holstein-Friesian. On the other hand, gender proved to be a significant factor influencing the amino acid profile of beef proteins, as the quantity of essential amino acids turned out to be significantly larger in females than in males. No statistical difference could be established for the non-essential amino acids and BV between the two genders.