Amino acid digestibility of protein concentrates given separately or together with cereal grains

In experiments with rats the amino acid digestibility of three protein concntrates (soya bean meal, herring meal, horse bean meal) was measured when these protein sources were given separately and together with cereal grains (barley, maize, oats or wheat). True digestibility of the individual amino acid components was in general close to the digestibility of the corresponding protein source. Furthermore it was found that the true digestibility of amino acids in a feed mixture is directly related to the amino acid digestibility of the individual protein components in the diets.