Extraction and analysis of free amion acids from sheep digesta

A routine procedure entailing three methanol‐chloroform‐water extractions and an ultrafiltration step was adopted to extract the free amino acids from freeze‐dried sheep digesta. Detailed estimation and idefltification of the amino acids both by thin‐layer electrophoresis (t.l.e,) coupled with thin‐layer chromatography (t.l.e.) and by using a Beckman IZOC analyser was undertaken, Generally, there was agreement between the two methods, the latter being preferred because several amino acids were not suficiently separated by the t.l.e. and t.l.c. methods. The t.l.e. and t.l.c. method, however, showed the presence of several unidentified ninhydrin positive compounds not detected during automatic analyser estimations. Detailed analysis of the digestive tract samples revealed that the free amino acids decreased in amount during passage through the animal. However, five amino acids had higher values in the ileum than in the duodenum.