Metabolizable energy and amino acid digestibility of decorticated extruded safflower meal

An experiment was conducted to determine TME and amino acid digestibility of several dehulled extruded safflower meals. Finely ground partially dehulled extruded (ESM), partially dehulled solvent-extracted (SESM), extensively cleaned dehulled and extruded safflower meal (CSM), or soybean meal 44 (SBM 44) was intubated to 9 fasted mature roosters with 40 g per rooster and total excreta was collected.The concentrations of all essential amino acids in CSM were higher than those in ESM and SESM. Also, compared with SBM 44, CSM was deficient in lysine, slightly higher in TSAA and tryptophan, but much higher in arginine. The AME(n) and TME(n) of CSM were 2,413 and 2,832 kcal/kg, respectively, and were higher than those of SBM 44 (P < 0.01). The true lysine digestibilities of CSM and SBM 44 were similar but were higher than those of ESM and SESM (P < 0.05). However, ESM, SESM, and CSM had similar true tryptophan and threonine digestibilities that were lower than that of SBM 44 (P < 0.05). With respect to TSAA, all feed ingredients under investigation had similar apparent and true digestibilities. In conclusion, extensive hull removal of safflower seeds followed by cold extrusion produced a low-fiber CSM rich in both energy and protein that makes it a promising feed ingredient for poultry.