differences between the two types of DDGS were small. The
differences in protein secondary structure indicate the difference
in protein molecular structure make-up. In our
study, the ratio of amide I area to amide II area and ratio of ahelix
to b-sheet in corn DDGS were in good agreement with
the previous study [6]. The molecular spectral differences of
protein molecular structure may partially explained the
difference between protein nutrient profiles and protein
utilization and availability in the rumen and intestinal in
dairy cattle. Although, the differences of corn DDGS were
detected from the 1st to the 5th samples in amide I and
amide II and their ratio. Most of corn DDGS could not be
distinguished from each other within the protein spectra
region ca. 1723 cm1e1480 cm1 based on CLA and PCA analyses
(Fig. 1a), except the 4th co-product samples are
different with remaining samples. When compared with the