The amino acid, collagen and mineral composition of preruminant calves

Abstract

Summary The amino acid, mineral and collagen composition of certain different components of the bodies of preruminant calves was determined. The amino acid composition (g/kg crude protein) of the empty bodies of preruminant calves was: hydroxyproline, 40; aspartic acid, 81; threonine, 40; serine, 44; glutamic acid, 129; proline, 81; glycine, 113; alanine, 71; cystine, 13; valine, 39; methionine, 17; isoleucine, 28; leucine, 69; tyrosine, 25; phenylalanine, 36; lysine, 64; histidine, 25; arginine, 70; tryptophan, 8. The hydroxyproline, proline and glycine contents were much higher than in bovine muscle because about one-third of the total protein of the calves was collagen, a protein particularly rich in these amino acids. The collagen content of the individual body components varied considerably as did their amino acid contents. There were also some marked differences in the contents of some of the major constituents and minerals in the individual components. In particular the internal organs and blood (component (6)) contained significantly lower concentrations of crude protein, ash, Ca, Mg and P but significantly higher concentrations of Cu and Fe.