Variation in lysine, threonine, and tryptophan availability in meat and bone meal as estimated by the slope‐ratio growth assay technique in growing rats

Abstract

Meat and bone meal (MBM) is an important protein source used in animal feeds. However, as the composition and availability of amino acids (AAs) in MBM fluctuate markedly, it is important to verify the magnitude of these parameters in different MBMs. In this study, the AA compositions of 19 MBMs were analyzed to confirm variations in lysine (Lys), threonine (Thr), and tryptophan (Trp), then which were compared with those of soybean meal (SBM) and fish meal (FM). Instability in Lys, Thr, and Trp availabilities in six MBMs were also considered after estimation using the sloperatio growth assay technique in rats. Variations in AA composition were evaluated using the coefficient of variance (CV: Standard deviation/Mean). CVs for Lys, Thr,